Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials
Founded at 2009


Abstracts archive


fh2023_cover_front

1. EXPERIMENTAL STUDIES OF NANOPARTICLES, NANOSYSTEMS, AND NANOMATERIALS – page 8

Alemasova N.V., Bugorskaya D.I., Burkhovetskii V.V., Volkova G.K., Glazunova V.A., Zelenskii M.Yu., Savoskin M.V.
Graphite oxide: peculiarities of investigation of this material by physical methods – page 8
Abstract: It is shown by physical methods that the preliminary preparation of samples affects the structure and properties of graphite oxide and partially reduced graphite oxide. The graphite oxide drying technique as the last synthesis stage determines its morphology and structural properties. At drying by sublimation method, the state of graphite oxide in aqueous suspension before the beginning of the process of self-ordering of its sheets is fixed, the data of X-ray diffraction analysis testifies its X-ray amorphous state, the dried graphite oxide appearance is a light yellow powder. Drying of graphite oxide aqueous suspensions at temperatures above room temperature is accompanied by the ordering of the graphite oxide structure under the action of the surface tension and Van der Waals orces with the dark brown film formation. It is shown by scanning and transmission microscopy methods that the method of separation of partially reduced graphite oxide from glass substrates, on which the product is dried, can lead to the formation of wrinkled or roll-shaped structures. When graphite oxide is examined by transmission electron microscopy, even a short exposure to ultrasound (used in the conventional method of depositing the material on a copper grid prior to examination) results in wrinkling and partial curling of the edges of graphite oxide nanoparticles. Mechanical grinding of graphite oxide leads to disordered graphite oxide structure and to the interplanar spacing increase.
Keywords: graphite oxide, structure, surface morphology, scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis.

Anofriev V.A., Antonov A.S., Ivanov D.V., Semenova E.M., Ivanova A.I., Tretiakov S.A., Afanasiev M.S., Sdobnyakov N.Yu.
Formation pattern of fractal relief for nanosized molybdenum films – page 17
Abstract: Some patterns of formation of the fractal relief of nanosized molybdenum films on the mica surface are considered using the atomic force microscopy. The tools and techniques for postprocessing and analyzing 2D images acquired through this specific research methodology have been thoroughly investigated. The significance of the contributions of errors and uncertainties to the final outcome of the acquired data is discussed. Additionally, a threshold detection method was applied to analyze the fractal dimension, allowing for the identification of areas of interest and exclusion of noise components, as well as regions not having scientific significance. The fractal dimension of the obtained agglomerates was determined at various scales, ranging from 0,5 to 3 µm. The next value Dc = 2,19 and Dc = 2,45 were obtained for the original images; Dc = 2,13 and Dc = 2,45, respectively, for the images processed using the threshold detection method. The obtained data provide prospects for further research and development of novel methods for synthesizing materials with specific properties.
Keywords: atomic force microscopy, magnetron sputtering, fractal dimension, molybdenum films, software.

Bernatskii D.P., Pavlov V.G.
Determining the evaporation energies of alkali and alkaline earth metal atoms using field desorption – page 32
Abstract: The desorption of cesium and barium atoms from a quasi-spherical nanostructured surface of a field emitter has been studied using the method of field desorption microscopy. The dependences of the desorbing electric field strength on the degree of cesium and barium coating of the rhenium and tungsten field emitter at migration equilibrium are obtained. Migration equilibrium occurs at a certain emitter temperature when, due to the surface diffusion, the concentration of adsorbate is redistributed on various surface areas depending on the local heat of evaporation of adatoms from these areas. It is shown that when the migration equilibrium condition is met on the nanostructured surface of the field emitter, on which there are flat low-index crystal faces with different output work, the desorption has an avalanche-like character with the removal of the entire adsorbate. This behavior of the field desorption is characteristic of atoms of alkaline and alkaline earth metals, associated with a sharper increase in the work function compared with an increase in the evaporation energy of the atom with a decrease in the adsorbate concentration. As a result, the ion desorption energy decreases with an avalanche-like increase in the desorption rate. Taking into account the same desorbing field on all parts of the surface, which follows from the characteristics of Fowler Nordheim, the heat of evaporation of adsorbate atoms on different parts of the surface with different work function is determined within the framework of the image forces model for field desorption.
Keywords: field desorption microscopy, atom evaporation energy, field emitter, rhenium, tungsten, alkaline and alkaline earth metals, migration equilibrium.

Bernatskii D.P., Pavlov V.G.
Field desorption of caesium and barium from graphen nanoclueters on the iridium surfaces – page 40
Abstract: The features of the field desorption of caesium and barium from the surface of an iridium tip with two-dimensional graphene nanoclusters on the surface are investigated. Both adsorbates are located both on the surface of iridium and carbon clusters, and in the intercalated state under the graphene film in the close packed planes of the iridium crystal. Field desorption proceeds in different ways. With an increase in the intensity of the applied electric field, the pulse removal of the adsorbate from the surface occurs. With further strengthening of the field in the case of caesium, desorption of adsorbate atoms from the intercalated state occurs. Caesium atoms come out from under the film, diffuse onto the surface of the cluster and are desorbed in the ion form. Barium atoms remain under the graphene film until the cluster is destroyed. The difference in the mechanisms of field desorption from graphene clusters is explained by the presence of a second electron on the valence shell of alkali metal atoms, which provides a chemical bond between the adsorbed atoms and the substrate. The only valence electron of alkali metal atoms during adsorption goes into the metal, and provides an electrostatic bond of the adsorbate with the substrate and electrostatic repulsion of the adatoms among themselves.
Keywords: field desorption, clusters, carbon, iridium, caesium, barium.

Bobreva L.A., Sidorov N.V., Palatnikov M.N., Gosteva A.N.
Investigation of the structural features of LiNbO3:Gd (0.002-0.26 wt.%) crystals by IR absorption spectra in the region of valence vibrations of hydrogen bonds – page 46
Abstract: Nonlinearly optical single crystals LiNbO3:Gd (0.001-0.26 wt.%) were grown by theCzochralskii method using the technology of direct doping charge of congruent composition. The defect structure of crystals in the region of valence vibrations of hydrogen bonds was studied by IR absorption spectroscopy. It was found that in the region of small concentrations of the doping impurity gadolinium on the IR spectrum there is a decrease in the widths of absorption bands. The gadolinium impurity with the concentration of 0.26 wt.% leads to a significant deformation of the oxygen octahedron due to the large ionic radius of the gadolinium cation and an increase in the O-O length. A new absorption band at 3488 cm-1 corresponding to the VLi-OH complex defect is registered on the IR spectrum. The calculation of the volume concentration of OH-groups showed the lowest value for LiNbO3congr crystal and the highest for LiNbO3:Gd(0.005 wt.%), which is related to the process of doping impurity entring into the structure and the increase in the number of point defect centers VLi necessary to compensate the structural defect GdLi2+.
Keywords: lithium niobate, defects, IR spectroscopy, hydrogen bonds, complex defects.

Bobreva L.A., Sidorov N.V., Palatnikov M.N., Pyatyshev A.Yu..
Features of the localization of dopping cations Tb3+ in a LiNbO3 crystal in the concentration range 0,1-2,21 wt.% – page 55
Abstract: LiNbO3:Tb (0,1 wt.%), LiNbO3:Tb (0,48 wt.%), and LiNbO3:Tb (2,21 wt.%) crystals were studied by the infrared absorption spectroscopy in the area of valence vibrations of OH- -groups. These crystals were grown by Czochralski method employing direct alloying of blend of the congruent composition. It was found that when the concentration of point defect centers of the cationic sublattice VLi was higher, than the concentration of impurity point defects TbLi, an absorption band with the frequency of 3487cm-1  was registered in the IR spectrum. This absorption band is associated with the violation of stoichiometry and the formation of a complex defect (VLi – OН) in the LiNbO3:Tb (0,1 wt.%), and LiNbO3:Tb (0,48 wt.%) crystals. A further increase in the concentration of the alloying impurity leads to a change in the O-O bond length, which affects the OH-bond length and the appearance of a new absorption band with a frequency of 3493 cm-1, which corresponds to the complex defect (TbLi – OН) in the LiNbO3 crystal. Due to non-uniform admixture in the LiNbO3:Tb crystal, clusters are formed to which the absorption bands with frequencies in the range of from 3100-3403 cm-1 to 3510-3580 cm-1 in the spectrum.
Keywords: single crystal, lithium niobate, rare-earth ion, valence group vibrations, complex defects.

Bolshakova N.N., Druginina N.Yu., Ivanova A.I., Ivanov D.A., Semenova E.M.
Hysteresis properties of PIN-PMN-PT single-crystal solid solutions – page 64
Abstract: The paper presents the results of a study of hysteresis properties based on analysis of dielectric hysteresis loops and temperature dependences of switchable polarization for solid solutions 24% Pb(In1/2Nb1/2)O3 – 49% Pb(Mg1/3Nb2/3)O3 – 27% PbTiO3 solutions. It follows from the experiment that at T = 293 K and strengths of the repolarizing field E = (140-301)·103 V·m-1, only partial switching of the crystal occurs. Saturated dielectric hysteresis loops of crystals are observed in a field of 271·10V·m-1 in two temperature ranges 373-383 K and 437-440 K. The temperature dependences of the permittivity and switchable polarization have two anomalies, the first of which correspond to the region of the phase transition of the crystal from the ferroelectric rhombohedral phase to the tetragonal one. At a temperature of about 450 K, the crystal passes into the paraelectric state. Electron microscopic studies of the PIN-PMN-PT crystal structure show that various surface areas contain inhomogeneities that differ in the compositional contrast from the matrix represented by chemical elements, the main mass percentage of which is oxygen and lead. The elemental composition of heterogeneities also includes titanium.
Keywords: single crystal solid solution, hysteresis, switching processes, permittivity, phase transition.

Bukreev A.P., Muratova E.N., Moshnikov V.A.
Film irradiation of perovskite structures with charged particles – page 75
Abstract: Hybrid halide perovskites of the ABX3 composition are promising materials for use in optoelectronics and photovoltaics. To enhance the efficiency of structures based on perovskite, simulating the influence of the environment on the structures in laboratory conditions, irradiating them with various charged particles, has become a relevant task. This study explores possible irradiation methods for films with perovskite structures using various charged particles, such as alpha and gamma particles, protons, and electrons. Additionally, the impact of these processes on the properties and application domains of such structures is assessed. The research results showed that films based on perovskites (for example, CsPbBr3) have a very fast response (τ ∼5 ns) to irradiation with both alpha particles (with energy of ∼5 MeV) and protons. At the same time, they have the ability to fully restore to the initial conditions in a few hundred milliseconds after the cessation of irradiation. It has been shown that organic-inorganic hybrid perovskites are more sensitive to the action of an electron beam than inorganic onesAn increase in the dose of gamma irradiation leads to a decrease in the band gap (from 2,35 to 2,14 eV), a shift in the photoluminescence peak towards longer wavelengths and a decrease in the resistance of the grain boundaries. The effect of the gamma radiation dose on properties makes perovskite thin films very useful as sensor materials.
Keywords: perovskites, irradiation, charged particles, solar energy, photoluminescence, ion beams, detectors.

Efremov I.N., Masloboeva S.M., Biryukova I.V., Teplyakova N.A., Palatnikov M.N.
Investigation of acoustic, optical and photorefractive properties of multicrystals of lithium niobate doped with zinc in the area of concentrations of 5,38-9,0 mol.% Zn – page 85
Abstract: Obtaining optical materials based on lithium niobate with controlled optical properties is animportant task of  modern materials science. To date the problem of obtaining heavily doped LiNbOcrystals of optical quality with a macroscopically uniform impurity distribution has not been solved. In this work a comparative analysis of studies of the acoustic, optical and photorefractive properties of LiNbO3:Zn lithium niobate single crystals obtained by direct and homogeneous doping from melts with concentrations of 5,38-9,0 mol% Zn has been carried out. The following methods have been used: piezoacoustics, photoinduced light scattering and laser conoscopy. The values of the static piezoelectric modulus have been determined. According to these values, all crystals are single-domain. Studies of crystals have confirmed the absence of a photorefractive effect in them. It was established that LiNbO3:Zn crystals grown on the basis of the method of homogeneous doping with concentrations in the melt of 6,8-9,0 mol% Zn are characterized by the highest structural and optical uniformity. This is of interest for the technology of growing large zinc-doped lithium niobate crystals by the Czochralski method.
Keywords: lithium niobate, zinc doping, single crystal, static piezoelectric module, photoinduced light scattering, laser conoscopy, optical uniformity.

Zigert A.D., Dunaeva G.G., Kuz`min N.B., Semenova E.M., Sdobnyakov N.Yu.
The fractal dimension behaviour of the domain patterns in ferrite-garnet films – page 98
Abstract: In this work, using a set of experimental techniques and specialized software, we studied bismuth-containing ferrite garnet films of various thicknesses and with different stoichiometric compositions grown on gadolinium gallium garnet substrates. The limiting magnetic hysteresis loops for defective and defect-free sections of films were obtained using the optical magnetometry method. The field dependences of the fractal dimension of magneto-optical images were also obtained. For various compositions and thicknesses of bismuth-containing ferrite-garnet films, ranges of changes in the fractal dimension were obtained. The fractal dimension was determined by the counting cube method. The mutual behavior of the field dependences of the fractal dimension and the first derivative of magnetization with respect to the field dM(H)/dH is analyzed. The characteristic features of the behavior of the first derivative of magnetization with respect to the field dM(H)/dH with a change in the film thickness, as well as for defective and defect-free sections of films, have been established.
Keywords: magnetic films, ferrite garnets, bulk defects, domain structure, fractal dimension, dM(H)/dH dependence.

Ivanov V.V., Malyshkina O.V., Kislova I.L., Ivanova A.I., Solnyshkin A.V.
Structural features and dielectric response of barium-strontium titanate ceramics – page 108
Abstract: In this work, we carried out a comparative study of the surface structure of bariumstrontium titanate Ba1-xSrxTiO3 ceramics of various compositions (x = 0,1; 0,2; 0,25; 0,3; 0,4 and 0,5) and the dielectric characteristics of samples in a wide temperature range. It has been found that with increasing the strontium content, a decrease in the density of ceramic samples is observed. An increase in the strontium concentration in the composition of the ceramics under study leads to a reduction in the average grain size by an order of magnitude, and fine grains from 2 μm to 200 nm. For all ceramic samples of barium-strontium titanate, there is a deviation of the elemental composition from the stoichiometric at the nanoscale. The closest to the stoichiometric composition in terms of the molar content of elements is the composition of the Ba0,75Sr0,25TiO3 samples. It was found that the samples of this composition have the highest value of the permittivity at room temperature. Temperature studies of the dielectric permittivity showed the existence of two maxima: at a temperature of 130°C, corresponding to the Curie temperature of pure barium titanate ceramics, and at lower temperatures in the range from 10 to 100°C, the second depends on the strontium content. The low-temperature maximum for the ε value corresponds to the diffuse transition of the solid solution Ba1-xSrxTiO3, whose relaxor properties are confirmed by deviation of the temperature dependence from the Curie–Weiss law. The samples of Ba0,75Sr0,25TiO3 composition have the most pronounced relaxor behavior.
Keywords: piezoelectric ceramics, barium– strontium titanate, lead-free materials, grain structure, permittivity.

Klychkov N.A., Simakov V.V., Sinev I.S.
Temperature dependence of Cu:SnO2 film conductivity in air medium – page 119
Abstract: Temperature conductivity studies of films based on Cu:SnO2 made by magnetron sputtering of the mixed target CuO/SnO2 have been carried out. Temperature conductivity dependencies were substantially nonlinear. It was found that the local conductivity minimum was observed near the temperature of 330°C. To explain the results, a mathematical model is proposed of oxygen adsorption in various forms on the surface of wide-bandgap semiconductors. It was assumed that oxygen particle adsorption resulted in energy levels of the acceptor type localized near the surface of the semiconductor. The simulation carried out within the proposed model showed qualitative and quantitative consistency of the calculation results and experimental data of the temperature dependence of conductivity of the formed gas-sensitive Cu:SnO2 layers in oxygen-containing atmosphere. An analysis of experimental temperature dependence showed that the local conductivity minimum is due to the process of dissociation of oxygen particles adsorbed in molecular form. The desorption energies of each form of adsorbed oxygen and the depth of their surface acceptor level are assessed.
Keywords: temperature dependence of conductivity, oxygen dissociation, tin dioxide, gas sensitivity model.

Kozodaev D.A., Gagarina A.Yu., Spivak Yu..M., Moshnikov V.A.
Structures on heteroepitaxial layers of PbTe(111)-ON-Si with stepped submicron surface relief – page 127
Abstract: A metrological stepped surface with atomically smooth edges, the heights of which have a calibrated size that is a multiple of the height of one monolayer, was obtained by using the example of epitaxial layers of lead telluride with a sublayer of calcium fluoride on (111) single-crystalline silicon substrate. The morphology of the relief was studied using atomic force microscopy. An assessment was made of the stepped relief resulting from the occurrence of mechanical stresses at the «epitaxial layer-substrate» interface. It has been established that the side walls of the steps are cut along crystallographic planes belonging to the {100} set and the walls of the steps are inclined at angles of 54,7° and 144,7° to the plane of the base of the test sample. Recommendations are proposed for the use of calibration samples for a series of epitaxial layers of lead telluride to evaluate the instrumental function of probes.
Keywords: scanning probe microscopy, atomic force microscopy, lead chalcogenides, nanomaterials, test sample.

Korolkov O.E., Stolyarov V.V.
Stress relaxation under tension by accompanyed current in ultrafine-grain titanium – page 135
Abstract: The article studies the effect of stress relaxation caused by strain stops and pulsed current on the tensile deformation behavior of Grade 4 ultrafine-grained titanium. The samples were deformed in the following modes: without current; continuously with current; with periodic current supply, periodic current supply during stops of strain. The microhardness of the working zone of the tested specimens was studied. Fracture studies of the failure zone were carried out. It is shown that, as a result of the continuous introduction of current during tension, the flow stresses decrease, and the elongation to failure increases. Periodic introduction of current, accompanied by strain stops, leads to a maximum increase in the relative elongation to failure due to stress relaxation. The relaxation effect of the pulsed current is manifested in a decrease in microhardness and the transition of the fracture type from a dimple-cup fracture to a predominantly dimple fracture.
Keywords: stress relaxation, tension, titanium, nanostructure, electroplastic effect, pulsed current, microhardness, fractography.

Kramynin S.P., Zobov E.M., Zobov M.E.
On the possibility of decomposition of complex photoluminescence spectra – page 148
Abstract: A method is proposed for decomposing the integrated photoluminescence spectrum into components based on the analysis of an identifier, which is the ratio of the first and second derivatives of the experimental data. The question of the limits of applicability of this method of decomposition of a complex photoluminescence spectrum has been studied in this paper. The definition of the sensitivity of the method is given on the example of an integral spectrum formed by two Gaussians. The evolution of the dependence of the used identifier on the wavelength is shown with a change in the distance between the maxima of the elementary components. By means of a synthetic experiment, dependences of the sensitivity on the ratio of the half-widths and intensities of the components of the integral spectrum are plotted. The dependences obtained are non-linear and have local maxima and minima. The use of the calculated dependences makes it possible to estimate at what overlap of the bands the decomposition is still possible, and at what it is no longer possible to separate the elementary component from the integrated spectrum.
Keywords: photoluminescence, spectrum, decomposition, ZnS, ZnO, modeling, integrated spectrum, Gaussian, luminescent analysis, synthetic experiment.

Lapin V.A., Kravtsov A.A., Suprunchuk V.E., Tarala L.V., Medyanik E.V., Malyavin F.F.
Synthesis and investigation of properties of composite ceramics LuAG: Ce / Al2O3 – page 157
Abstract: The purpose of this work was to study the effect of the aluminum oxide impurity content onthe features of  vacuum sintering, optical and luminescent properties of composite ceramics LuAG:Ce / Al2O3. Ceramic powders LC-1, LC-2, LC-3 of the composition Lu2,98Ce0,02Al5O12 / Al2Owere synthesized, where the corundum content was 0, 10, 20 wt.% respectively. The dynamics of shrinkage of ceramic compacts by dilatometry, morphology and elemental analysis of the surface of sintered ceramics LuAG are investigated: Ce / Al2O3 – by scanning electron microscopy. Light transmission and luminescence spectra were obtained. It is shown that with an increase in the content of corundum in the composition of ceramic powder, the temperatures of the beginning and end of shrinkage increase. In this case, the residual porosity is concentrated in areas of ceramics containing mainly corundum crystallites, as a material with a higher sintering temperature. It was revealed that the inclusion of the corundum phase prevents the uncontrolled growth of ceramic grains. Composition with a corundum content of 10 wt.% showed the highest value of luminescence intensity. At the same time, with an increase in the proportion of corundum in composite ceramics, a slight broadening of the luminescence spectra was observed.
Keywords: : LuAG:Ce, ceramics, aluminum oxide, luminescence, optical properties, sintering.

Lyakhova M.B., Semenova E.M., Rakunov P.A., Karpenkov A.Yu., Sinkevich A.I., Fedorov M.V.
Hysteresis structure and magnetic properties of (R, Zr)(Co, Cu, Fe)Z (R = Sm, Gd) alloys – page 169
Abstract: The results of an experimental study of magnetization reversal processes of (R,Zr)(Co,Cu,Fe)Z (R = Sm, Gd) alloys taking into account micro- and nanostructure are presented. To create a highly coercive state in the samples, they were isothermally annealed at 800°C for 8-24 hours. The duration of annealing affects the formation of the nanostructure of alloys of this type. Based on magnetic measurements performed using a vibration magnetometer, magnetic hysteresis loops and graphs of the dependence of the coercive force on the chemical composition and duration of heat treatments were obtained, and the range of changes in the temperature coefficient of magnetic induction was determined depending on the relative content of Sm and Gd in the samples. Data on micro- and nanostructure were obtained using optical and scanning probe microscopy. The correlation relationships between the micro- and nanostructure parameters and the magnetic properties of the studied alloys are described. It was found that the highest values of the coercive force are achieved in an alloy in which the value is x = 0,5.
Keywords: rare earth intermetallic compounds, hysteresis, coercive force, magnetization, microstructure, nanostructure.

Mitchenko A.S., Malyshkina O.V., Guseva O.S., Ivanova A.I.
Stabilization of the dielectric properties of solid solution ceramics based on calcium–barium niobate – page 178
Abstract: In this work, we studied the effect of a modifying additive of finely dispersed polystyrene (2 wt.%) on the dielectric and pyroelectric properties of the ceramic samples Ca0.3Ba0.7Nb2O6 (CBN30) and solid solutions based on it with the addition (5%) of SrTiO3 or LiTaO3, obtained by the solid-phase synthesis method. It is shown that the presence of polystyrene during the sintering of solid solution ceramics based on CBN30 leads to the formation of nanosized pores in the samples and, as a result, leads to a significant decrease in the dielectric losses and a change in the nature of the permittivity dispersion in a wide frequency range of fabricated samples. As a result, the shape of the dispersion diagrams of the ceramics based on CBN30 became similar to the dielectric dispersion of industrial samples of the piezoelectric ceramics of lead zirconate-titanate. The studies of the pyroelectric effect on polarized ceramic samples based on CBN30 revealed that the samples sintered with the presence of polystyrene, in contrast to the samples sintered without polystyrene, have a uniform polarization distribution over the thickness.
Keywords: piezoelectric ceramics, barium-calcium niobate, lead-free materials, modifiers, grain structure, permittivity.

Molokanova O.O., Karmokov A.M., Molokanov O.A., Karmokov M.M., Khasanov A.I., Dyshekova A.Kh.
Fundamental absorption and band gap of glasses S87-2, S78-4, S78-5 – page 189
Abstract: In special glasses for electronic technology of brands S87-2, S78-4 and S78-5, the effect of thermal processes on the spectra of optical absorption in the wavelength range from 200 to 1100 nm was investigated. Glasses were studied both in the initial state and after annealing at various thermodynamic conditions: in an atmosphere of natural air and in vacuum at temperatures of 400 and 500°С, as well as in flow-through hydrogen at a temperature of 400°С. The influence of the medium, temperature and annealing time on the dispersion dependences of the absorption of the studied glasses was established. It was found that the time of absorption by some glass components has a significant effect on the own absorption of annealing in hydrogen. The edge of the fundamental absorption is determined and the width of the prohibited zone of the resulting nanocrystalline phases is estimated. The width of the prohibited zone of the nanocrystalline phases formed during the annealing of samples at high temperature, according to the results of optical measurements, is from 2,0 to 3,7 eV.
Keywords: glasses, intrinsic absorption, nanocrystal, band gap.

Staritsyn M.V., Kiselev D.A., Pronin V.P., Krushelnitsky A.N., Senkevich S.V., Kaptelov E.Yu., Pronin I.P.
Peculiarities of the microstructure and properties of thin spherolitic PZT films formed by a two-stage radiofrequency magnetron deposition method – page 196
Abstract: The paper presents the results of experimental studies of the microstructure and piezoelectric properties of thin lead zirconate-titanate films characterized by either an island structure of radially radiant spherulites located in a low-temperature pyrochlore matrix or a block single-phase spherulitic structure with different linear block sizes. Changing the size of the blocks within 10-50 µm was achieved by varying the distance from the target to the substrate in the range of 30-70 mm, leading to a change in the heating temperature of the substrate in the radio-frequency magnetron sputtering of a ceramic target during film deposition on a «cold» platinized silicon substrate. The temperature of subsequent annealing for the crystallization of the perovskite phase was 550°C for island films and 580°C for single-phase films. Scanning electron microscopy methods have revealed anomalous dependences of the rotation of the growth axis with the growth of the linear dimensions of spherulites, reaching a value of 1,2 deg/μm, and other microstructural parameters of thin films. The observed phenomena were caused by lateral mechanical stresses arising during the solid-state transformation from the pyrochlore phase to the perovskite phase, accompanied by a change in the density of the films. At tensile stresses of the order of the elastic limit, this led to the appearance of intra-block high-angle boundaries. The behavior of lateral polarization was studied by the method of force microscopy of the piezoelectric response and it was shown that tensile mechanical stresses in spherulites lead to the orientation of the lateral polarization vector in the radial direction.
Keywords: lead zirconate-titanate thin films, pyrochlore-perovskite phase transformation, spherulite microstructure, piezoresponse force microscopy.

Teplyakova N.A., Sidorov N.V., Palatnikov M.N.
Optical properties of double doped LiNbO3:Gd:Mg crystals – page 207
Abstract: By direct alloying of congruent melt with magnesium and gadolinium oxides, compositionally uniform nonlinear optical single double doped crystals with different content of dopants have been grown: LiNbO3:Gd3+(0,003):Mg2+(0,65 wt. %), LiNbO3:Gd3+(0,23):Mg2+ (0,75 wt. %) and LiNbO3:Gd3+(0,25):Mg2+(0,75 wt. %). The results obtained by laser conoscopy and photoinduced light scattering indicate a high structural perfection of the grown crystals. The results give grounds to assert that LiNbO3:Gd:Mg crystals are close to a stoichiometric crystal in some of their properties. A low value of the coercive field (≈2,3 kV/cm) is one of such properties of stoichiometric and magnesium-doped LiNbO3 crystals, which are important for creating materials for laser radiation conversion on periodically polarized submicron-sized domains with flat boundaries. In this case, the grown LiNbO3:Gd:Mg crystals have a much higher optical uniformity than a stoichiometric crystal. Crystals of LiNbO3:Gd3+(0,003):Mg2+ (0,65 wt. %) and LiNbO3:Gd3+(0,23):Mg2+ (0,75 wt. %) have the highest optical uniformity and the absence of the photorefraction effect. Increase of gadolinium concentration to 0,25 wt. % leads to increased distortion of the conoscopic pattern and to the appearance of a significant photorefractive response of the LiNbO3:Gd3+(0,25):Mg2+(0,75 wt. %) crystal.
Keywords: lithium niobate, crystal, defects, laser conoscopy, photorefractive properties.

Teplyakova N.A., Sidorov N.V., Palatnikov M.N.
Features of the defect structure of a LiNbO3:Cu (0.015 wt.%) single crystal – page 215
Abstract: By direct alloying of melt with copper oxide, а compositionally uniformity LiNbO3:Cu (0,015 wt%) single crystal doped with a photovoltaically active copper dopant has been grown. The optical properties of the single crystal have been studied by photoinduced light scattering. The values of the diffusion and photovoltaic fields were calculated for the studied crystals based on the intensity and magnitude of the opening angle of the speckle structure of the photoinduced light scattering. Significant differences in the photoinduced light scattering patterns and in the values of the photoinduced light scattering photoelectric parameters of nominally pure crystals of congruent and stoichiometric compositions and a LiNbO3:Cu (0,015 wt%) crystal have been found. It has been established that when a congruent lithium niobate crystal is doped with copper cations, the diffusion field increases, the photofoltaic field decreases, and the band gap in the crystal decreases noticeably. In contrast to the crystal of stoichiometric compositions, the photovoltaic mechanism remains the predominant mechanism of photorefraction for crystals of congruent composition and LiNbO3:Cu (0,015 wt%). Photoinduced light scattering data indicate the presence of a LiNbO3:Cu(0,015 wt.%) crystal in the band gap high density of small energy levels that increase the effect of photorefraction and electrical conductivity of the crystal.
Keywords: lithium niobate, crystal, defects, photorefractive properties, photovoltaic fields, band gap.

2. THE THEORY OF NANOSYSTEMS – page 223

Andre E., Tsirulev A.N.
Model of a three-qubit cluster in a thermal bath – page 223
Abstract: This work studies a mathematical model of a quantum cluster consisting of three qubits and being in thermal equilibrium with the environment. The effective Hamiltonian is invariant under permutations of qubits and consists of two parts. The first part is similar to the Heisenberg XYZmodel with internal two-qubit interaction, while the second includes three-qubit interaction with the thermostat. Such a quantum system admits a fully analytical investigation and is considered in the context of mathematical modeling of quantum metamaterials, in which nanoclusters are elementary structural units with the strong internal interaction of qubits and the relatively weak coupling with the environment. For the Hamiltonian, we construct an orthonormal basis of eigenvectors, which includes the maximally entangled W-state. We also obtain the density operator of the cluster state in explicit form, and study the temperature dependences of the thermodynamic characteristics of the cluster: the partition function, entropy, and free energy. It is shown that the conditions of thermal equilibrium in this quantum system are satisfied at temperatures from 0,2 K to microkelvins, which correspond to the operating range of modern quantum logic elements and quantum simulators.
Keywords: cluster of qubits, Hamiltonian, Pauli basis, operator exponential, density operator of a state, Gibbs-von Neumann state, partition function, entropy, free energy.

Apekov A.M., Shebzukhova I.G.
Contribution of the dispersion interaction to the interface energy of cobalt crystals at the boundary with nonpolar organic liquids – page 231
Abstract: The active implementation of devices based on the use of the properties of the metalorganic interface makes it important to study characteristics of such interfaces, especially of the metalorganic framework structures. The of these structures with the necessary properties is possiblesince one can vary the elemental composition in the  active metal centers as well as the organic ligandsbinding these centers. In this regard, understanding the  properties and nature of the interaction at the interface of a metal with organic substances becomes of primary interest. In this work, within the framework of the electron-statistical method, a correction to the interfacial energy of cobalt at the interface with non-polar organic liquids for the dispersion interaction of the Wigner-Seitz cells is obtained. The dependences of the dispersion correction on the orientation of the metal crystal and the permittivity of the organic liquid are determined. It is shown that the contribution of the dispersion correction to the interfacial energy is positive and decreases with an increase of the permittivity of the liquid.
Keywords: interfacial energy, dispersion contribution, electron-statistical method, non-polar organic liquid, cobalt.

Aref`eva L.P., Duka V.V., Drogan E.G.
Investigation of the morphology and topology of lamellar and grained pearlite from 1.1625 steel at the submicron level – page 239
Abstract: The paper presents the results of a study of the submicron structure of carbon eutectoid steel by the atomic force microscopy, carried out in accordance with current international standards. The study was carried out on samples obtained in two ways: complete annealing and annealing for granular perlite. The first sample had the structure of lamellar perlite, the second – granular pearlite. The presence of these structures was controlled by optical microscopy and hardness measurements by the Rockwell method. Sample preparation included cutting, grinding, polishing, and etching. The quantitative assessment of the structural components of perlite was carried out using the ImageJ application package. The volume fraction of ferrite was about 88%. The topology and morphology of the surfaces are studied by atomic force microscopy in the discontinuous-contact mode. The amplitude characteristics of the surfaces, the shape and size of the structural components of perlite are determined. It is shown that the performed analysis of the submicron structure makes it possible to uniquely identify the phase components of the steel.
Keywords: eutectoid steel, granular perlite, lamellar perlite, submicrostructure, atomic force microscopy.

Barabanova E.V., Kondratev S.E., Ivanova A.I.
Structure and dielectric properties of Ti-doped KNN ceramics – page 246
Abstract: The work is devoted to investigation of the influence of the technology for producing potassium sodium niobate ceramics with an acceptor impurity Ti4+ on its structure and dielectric properties. The aim of the work was to determine ways to obtain a single-phase composition of doped ceramics and the role of the TiO2 modifying impurity. It is shown that the substitution of niobium by titanium for preserves the cubic shape of potassium sodium niobate grains, increases dielectric losses and causes significant migration polarization. The latter leads to the fact that the maximum temperature dependence of the dielectric permittivity at low frequencies is not observed for the studied ceramics. The shift of the phase transition temperature caused by doping is not observed. In all samples, despite the heterogeneity of the elemental composition and grain structure, the phase transition temperature corresponds to the phase transition temperature of pure potassium sodium niobate ceramics.
Keywords: sodium potassium niobate, ferroelectric solid solutions, dielectric permittivity, acceptor dopants, phase transition.

Belyaeva I.N., Korsunov N.I., Chekanov N.A., Chekanov A.N.
Semi-classical calculations of energy levels and wave functions of hamiltonian systems with one and several degrees of freedom based on the method of classical and quantum normal forms – page 255
Abstract: The paper presents two schemes for the sequential construction of the classical normal form and its quantum analogue for some classes of classical Hamiltonian systems. For quantum normal forms, a method for solving their eigenvalue problem is indicated. Based on these normal forms, a semi-classical method for solving Schrodinger equations for classical Hamiltonian systems under their quantum consideration is proposed. With this proposed method, some quantum problems were solved and it was found that this method gives a very accurate prediction for energy levels. However, this accuracy in the field of the existence of classical chaos is deteriorating. The same semiclassical method solved the quantum problem for a flat hydrogen atom in a homogeneous magnetic field. The proposed method allows carrying out all calculations using modern computer systems of analytical calculations.
Keywords: classical normal form, quantum analog of normal form, Weyl-McCoy rule, energy levels, eigenfunctions, mathematical modeling.

Kul’kov V.G.
Contribution of grain boundaries with matching planes to internal friction – page 264
Abstract: In nanocrystalline metals, there are grain boundaries that, under the influence of shear stresses applied along them, move along the normal. Such boundaries combine two types of the grain boundary deformation – mutual grain slippage along the boundary and its migration. This relationship is easily explained in the model of intercrystalline boundaries with mating crystallographic planes. By solving the differential equation under the action of alternating voltage, the functional dependence of the boundary displacement on the coordinate and time is found. Based on this, the value of the energy dissipated during the oscillation period and the expression for the internal friction caused by the contribution of such boundaries are found. It has the character of a Debye peak. The activation energy of the process is equal to the activation energy of the grain boundary self-diffusion. An atomic mechanism of the boundary motion is proposed, which is based on diffusion processes between extended steps of atomic scale in the boundary.
Keywords: grain boundaries, crystallites, matching planes, boundary migration, diffusion, vacancies, relaxation time.

Magomedov R.A., Akhmedov E.N.
Calculation of CO2 P-ρ-T properties in the temperature range from T = 400 K to T = 1700 K – page 274
Abstract: Сalculation of the carbon dioxide state equation isotherms in the temperature range from T = 400 K to T = 1700 K is presented. Implemented calculation method is a refinement of the previously proposed approach based on the fractal state equation and specially developed software Fract EOS. The calculation results are in good agreement with the experimental data. It is shown, that the fitting parameter α of the fractal state equation for carbon dioxide does not depend on temperature. The density dependence can be accurately approximated using the polynomial. This fact simplifies the calculation of isotherms in a wide temperature range, and allowed to make the calculation for temperatures, that are not presented in the tabular reference data. The obtained results show that the proposed equation of state is suitable for studying not only simple substances like noble gases, but also for more complex substances, such as carbon dioxide.
Keywords: equation of state, integral-differentiation of fractional order, Maxwell relations, Helmholtz potential, partition function, carbon dioxide, isotherm, thermophysical properties.

Tvardovskiy A.V.
Simulation of adsorbostriction in microporous adsorbents – page 282
Abstract: In this work, models of elastic adsorption deformation of microporous adsorbents with different micropore geometries are proposed, which make it possible to relate changes in the relative linear dimensions of macroobjects (adsorbents) and micropores. Model No. 1 is a model of elastic adsorption deformation of microporous adsorbents upon interaction with gases. Model No. 2 corresponds to the model when the micropores are plane-parallel slots of limited size. Obviously, the proposed equations can be used in constructing the general thermodynamics of adsorption processes and adsorption theory, as well as in calculating the thermodynamic functions of adsorbents. In particular, changes in the internal energy, enthalpy, and entropy of the adsorbent during its deformation can be calculated. Thus, it will be possible to reveal the contribution of the non-inert adsorbent to the measured heats of adsorption. The developed approach contributes to the development of the thermodynamics of adsorption processes and the construction of a general theory of adsorption, taking into account the contribution of the adsorbent.
Keywords: adsorption, absorption, adsorbostriction, deformation of adsorbents, microporous adsorbents, dilatometric studies, adsorption thermodynamics.

Shebzukhova I.G., Aref`eva L.P.
Surface energy and electron work function for polimorphyc modifications of titanium – page 288
Abstract: In this work, the surface energy of titanium crystal faces was estimated using theelectron-statistical method,  taking into account the contributions of the dispersion, polarization, and oscillation corrections. Using an analytical relationship, the values of the work function of close-packed faces of polymorphic modifications of titanium are calculated from the values of the surface energy of single crystals taking into account the crystal structure. The influence of polymorphic transformation and temperature on the anisotropy of the studied properties is shown. Based on the values of the surface and interfacial energies, which consist of the average configurational energy and the energy of chemical interaction of two parts of the metal, the cohesive energy of α- and β-titanium is estimated and its dependence on temperature is shown. On the example of tungsten-titanium and molybdenumtitanium systems, the fundamental possibility of calculating the change in the work function depending on the concentration of the surface-active component in bimetallic systems is shown, which makes it possible to predict the service life of the material.
Keywords: surface energy, electron work function, anisotropy, polymorphic modifications of titanium, cohesion energy.

Shishulin A.V., Shishulina A.V.
Influence of the initial composition on the phase equilibria in the case of the solid phase separation in binary alloy nanoparticles (exemplifying on the W-Cr system) – page 299
Abstract: Due to a unique set of physico-chemical properties, nanoparticle-fabricated heavy tungstenpseudo-alloys with  the ultrafine-grained structure have become an object of a strong interest among researchers in the case of the up-to-date additive powder metallurgy technologies. In this paper, the peculiarities of the phase composition have been simulated in the framework of a thermodynamic approach to core-shell nanoparticles of a stratifying sold solution using the heavy W-Cr pseudo-alloy as an example. For a two-component system with the phase separation in the solid state, a specific effect has been demonstrated which consists in the fact that, unlike system in the macroscopic state, it is not only the volume fraction of co-existing phases but also their equilibrium composition varies depending on the initial composition of a the system. For two different heterogeneous states of a coreshell structure, the thermal stability areas have been obtained along with temperature-dependent equilibrium phase compositions of the system in each state. A thermodynamic interpretation of the obtained results has been described based on three possible mechanisms of reducing the free energy of the system.
Keywords: nanoparticles, phase separation, chemical thermodynamics, solubility, core-shell, tungsten, chromium.

Shishulin A.V., Shishulina A.V.
Several notes on the elastic properties of mesoporous materials – page 308
Abstract: In this paper, the dependence of the Young’s elastic modulus of a mesoporous material on the geometric characteristics (volume and shape) of pores has been analyzed. The geometric characteristics of pores have been determined in the framework of the fractal-geometry approach by the values of their effective diameter and fractal dimension. The presented estimates demonstrate that the effect (being characteristic of nanoscale particles), which consists a significant dependence of elastic moduli on the size and shape of a particle, can also be realized in mesoporous materials (the pore size being form 5 up to 50 nm) while the mesoporous samples themselves can be of macroscopic dimensions. Using the example of mesoporous silver, it has been shown that reducing the pore size and «complicating» the pore shape lead to a significant decrease in the Young’s elastic modulus. The results have been obtained in the framework of the cohesive energy-based model.
Keywords: elastic modulus, mesoporous materials, fractal dimension, cohesion, size distributions, Hardy-Ramanujan-Rademacher formula.

El Zanin A.R., Boroznin S.V., Zaporotskova I.V., Boroznina N.P., Kozhitov L.V., Popkova A.V.
About the possibility of applying empirical methods of estimation of standard enthalpies of formation of organic compound for fullerenes – page 317
Abstract: Due to the high practical significance and, as a consequence, active study of carbon nanomaterials, the question of methods for investigating their physicochemical, in particular, thermodynamic properties is relevant. In the present work, several approaches are considered to estimate the standard enthalpy of formation of fullerenes in the gas phase. The standard enthalpies of formation of C60 and C70 fullerenes in the gas phase have been calculated using the Laidler, Franklin, Souders-Matthews-Hurd and Joback-Reid methods. A number of analytical dependences of the standard enthalpy of formation in the gas phase on the number of carbon atoms in fullerenes molecules were obtained. The obtained values were compared with experimental data and the relative error of calculation was determined. It is concluded that the proposed methods are limitedly applicable for determination of standard enthalpy of formation of fullerenes in the gas phase. The obtained values of the standard enthalpy of formation by the most satisfactory method from the considered ones for fullerenes C60 and C70 are 2448,90 and 2857,05 kJ/mol, and the relative errors are 4,44% and 5,95%, respectively. This is the Souders-Matthews-Hurd method. The presented analytical dependences allow for an express estimation of the standard enthalpy of formation of fullerenes in the gas phase with a small amount of input data.
Keywords: additive calculation schemes, carbon nanomaterials, thermodynamic properties.

Yurov V.M., Goncharenko V.I., Oleshko V.S.
Primary nanocracks in nitrides, borides, and carbides of refractory metals – page 328
Abstract: A model is proposed that can be used to calculate the length of a nanocrack in a solid body. The nanocrack length in nitrides, borides, and carbides of refractory metals turned out to be in the range 1<L<3 nm. Theoretical and experimental methods for studying nanocracks are discussed. The theory gives a length interval 0<L<2 nm for silicon polycrystals. X-ray and electron microscopic methods give the thickness of cracks in the metal in the range of tenths and hundredths of a micron. The recently proposed method of fractoluminescence for the destruction of minerals with a duration of signals of about 50 ns, and the time interval between them varied from about 0,1 to 1 μs, made it possible to reveal nanocracks in oligoclase during the destruction of its surface in the range of 10<L<20 nm, which coincides with the one in proposed by us model. More examples of the formation of nanocracks in solids can be cited. In other words, we propose to call the direction of condensed matter physics «physics of nanocracks», which differs from the «theory of cracks» both in its experimental detection and in the method of its calculation.
Keywords: nanocrack, surface layer, metal, fracture, surface, model, micron.

Yurov V.M., Zhangozin K.N.
Surface thickness water and ethanol – page 338
Abstract: A theoretical model is proposed that allows one to determine the thickness of the surface layer of liquid R(I). For water and ethanol it turned out to be 1,1 nm. As a result, ethanol is unlimitedly soluble in water. Methyl acetate, benzene and toluene (R(I) of above 1,4 nm) form azeotropic mixtures with water. Glycerol, nitrobenzene and mercury (R(I) greater than 3 nm) are practically insoluble in water. From the proposed model, we can conclude that the surface layer of the liquid is a nanostructure with size effects. It is of interest that the thickness of the surface layer of water coincides with the thickness of the surface layer of iron, cobalt and nickel. The work of adhesion and elastic constants for water and ethanol, including Young’s modulus, were also found. It was established that the elasticity of water is only 100 times less than the elasticity of steel, i.e. water can be considered as an incompressible substance, and the internal friction in water is three times greater than in ethanol. It is also shown that the universal element of the geometry of spaces of liquid systems is the tetrahedron, which corresponds to sp3 hybridization of interatomic or intermolecular bonds.
Keywords: surface layer, water, ethanol, liquid, layer thickness, cluster.

3. FIRST PRINCIPLES AND ATOMISTIC MODELING – page 350

Barbin N.M., Yakupova L.V., Terent’ev D.I.
Thermal stability of fullerenes from the C28-C50 series in a nitrogen atmosphere – page 350
Abstract: In order to study the thermal stability of fullerenes Cn (n = 28, 32, 44, 50) in a nitrogen medium during the transition from the condensed phase to the gas phase and further reactions in the vapor phase, the method of thermodynamic modeling was used. Based on the results of the calculation, chemical reactions in the Cn–N2 system were compiled and temperature intervals wereidentified for each reaction. In this work, a comparative  study of the thermal stability ranges of Cfullerenes in the condensed and gas phases has been carried out. As a result of heating, the physicochemical processes occurring in the carbon-nitrogen system are distinguished, which can be divided into three groups: reactions occurring in the condensed phase, between the condensed and gas phases, and sublimation with thermal dissociation. It is clearly demonstrated that with an increase in the number of carbon atoms in the condensed phase, fullerenes exhibit their thermal instability, in contrast to the solid solution of fullerenes. This study is one of a series of works devoted to the properties of nanoparticles in nitrogen atmosphere, which can be used in the development of new flame retardant compositions.
Keywords: fullerenes, thermal stability, thermodynamic modeling, physical and chemical process, chemical reactions.

Blinov A.V., Pirogov M.A., Gvozdenko A.A., Golik A.B., Rekhman Z.A., Kolodkin M.A., Filippov D.D.
Computer quantum-chemical modeling of the interaction of selenium nanoparticles with quaternary ammonium compounds – page 357
Abstract: In this paper, a computer quantum-chemical simulation of the interaction of selenium nanoparticles with quaternary ammonium compounds was carried out, in which models of molecular complexes, electron density distribution, as well as higher populated and lower free molecular orbitals were obtained. For the presented molecular systems, the total energy of the molecular complex E, the difference in the energy of the quaternary ammonium compound molecule and the system «quaternary ammonium compound-selenium nanoparticles» ΔE, the energy of the highest occupied molecular orbital EHOMO, the energy of the lowest unoccupied molecular orbital ELUMO, and the chemical rigidity of the system η were calculated. As a result of data analysis, it was found that the interaction of selenium nanoparticles with quaternary ammonium compounds is energetically advantageous (ΔE > 11991 kcal/mol). The optimal system of interaction of selenium nanoparticles with quaternary ammonium compounds is the «cetyltrimethylammonium chloride-selenium nanoparticles» system, which is due to the highest value of the energy difference (ΔE = 11991,79 kcal/mol). Based on the analysis of the obtained models of molecular systems, it was found that when a quaternary ammonium compound interacts with selenium nanoparticles, the electron density is shifted and new molecular orbitals are formed, which indicate formation of a chemical interaction between the molecules. Next, IR spectroscopy of selenium nanoparticles stabilized with cetyltrimethylammonium chloride was performed. Based on the data obtained, it is found that there is a decrease in the intensity of the bands, in comparison with the IR spectrum of cetyltrimethylammonium chloride, in the regions from 2851 to 3026 cm-1 and from 1265 to 1377 cm-1, characteristic of the CH2 and CH3 groups, which indicates the presence of cetyltrimethylammonium chloride molecules oriented with the hydrophobic side to selenium particles on their surface. After that, the morphology of selenium particles was studied using the transmission electron microscopy method. As a result of the analysis of transmission electron microscopy images, the formation the layer of the quaternary ammonium compound on the surface of selenium particles with a diameter of 25 to 60 nm was confirmed.
Keywords: .

Gafner S.L.
To the problem of application of nanoclusters Ag-Cu in plasmonics – page 367
Abstract: The magnitude of the localized surface plasmon resonance (LSPR) in metal nanoparticles is determined by many factors. Thus, with an increase in their average linear size, the maximum position of the LSPR peak shifts towards long waves. However, the position of the LSPR maximum is affected to a greater extent by the material of the nanoparticles. Changing the average particle diameter fromD = 7 nm to D = 60 nm makes it possible to  vary the position of the LSPR maximum in the range of about 50 nm. However, with a smooth change in the composition of binary nanoparticles, it can already be varied within about 120 nm. Therefore, copper-silver alloy nanoparticles are of great practical interest due to the possibility of fine-tuning the plasmonic effects present in them by changing the composition, size, shape, and structure of the nanoparticles. Based on the results of the analysis of the available experimental data, it was concluded that it is possible to control the internal structure and shape of Ag-Cu nanoparticles in order to shift the plasmon resonance peak and enhance it.
Keywords: : nanoclusters, silver, copper, crystallization, structure, computer simulation, tight-binding.

Gafner S.L., Redel L.V.
Evaluation of the structure and shape of the experimentally obtained Ag nanoparticles – page 377
Abstract: Silver is one of the most promising nanomaterials for plasmonic applications due to its low cost as well as the ease with which it can be prepared into nanoparticles with controlled size and shape. By now, it has already become clear that it is the shape and internal symmetry of nanoparticles that can significantly affect the scattering and absorption of a light wave, since without the formation of a strong dipole, these effects in nanoparticles will be insignificant. Therefore, the main objective of the study was a theoretical analysis of the processes of formation of the external and internal structure of silver nanoclusters obtained by some methods of physical synthesis. To do this, we studied highresolution electron microscopy data for the initial and annealed silver nanoparticles formed on a carbon substrate by vacuum thermal evaporation and having sizes from 2,0 to 10,0 nm. It has been established that, as a result of annealing, the number of small nanoparticles (D< 3,5 nm) decreases by approximately 2 times, and the proportion of nanoparticles with icosahedral and decahedral faceting increases by approximately 1,5 times. Based on the analysis performed, conclusions were drawn about the possible features and mechanisms of formation of various types of symmetry in synthesized Ag nanoparticles.
Keywords: nanoclusters, silver, crystallization, structure, computer simulation, high-resolution transmission electron microscopy.

Gafner Yu.Ya., Ryzhkova D.A., Gafner S.L., Cherepovskaya A.A.
Features of crystallization Ag-Au alloy nanocusters – page 387
Abstract: In the production of SERS (surface enhanced Raman scattering) substrates, two mainapproaches to the  formation of an array of plasmonic nanoparticles are used: photolithography and chemical methods. Each of them has its own advantages and disadvantages. Vacuum thermal evaporation can also be used. It was chosen for analysis by computer simulation. For this, molecular dynamics simulation of the processes of crystallization of an array of binary Ag-Au nanoparticles was used, which makes it possible to smoothly control the plasmon resonance wavelength. Three arrays of Ag-Au NPs with a diameter of 2,0; 4,0 and 6,0 nm of various target compositions from Ag90Au10 to Ag50Au50 were created. They were subjected to the procedure of cooling from the melt with different rates of the thermal energy removal. In the course of modeling the formation of the internal structure of Ag-Au nanoparticles, conclusions were drawn about the dependence of these processes on the target composition, size, and level of thermal exposure. Based on the regularities obtained, adjustments were made to the technological process of creating SERS substrates using binary Ag-Au nanoparticles.
Keywords: nanoclusters, silver, gold, crystallization, structure, computer simulation, tight-binding.

Gafner Yu.Ya., Ryzhkova D.A.
Analysis of absorption processes on the surfaceof a nanocompacted gas sensor – page 395
Abstract: It is well known that gas absorption by a semiconductor surface leads to a change in its electrical conductivity. This phenomenon has become the basis for the technical production of various gas sensitive sensors. Near the particle surface, due to the absorption and subsequent ionization of oxygen molecules, a surface zone is formed that is depleted in free charge carriers. The thickness of this zone is comparable to the Debye length and depends on the oxygen pressure on the particle surface. Depending on the size of the particle and the degree of their connection, there can be either conductive contacts or contacts of the Schottky barrier type between them. All this leads to a different kind of relationship between the conductivity and the concentration of the gas being determined. Since the sensitivity is based on chemical reactions between the surface of a solid body and gas molecules, the most demanded are materials with a large surface-to-volume ratio and a high degree of porosity, i.e. nanoparticles. In the present work, the main possible mechanisms of absorption of gas molecules by compacted nanoparticles are considered and their analysis is carried out.
Keywords: absorption, semiconductors, nanocompacted material, gas sensors, simulation.

Devitsky O.V.
Effect of bismuth content on the structural and electronic properties of GaAs1-yBiy: first principles calculations – page 404
Abstract: A theoretical study of the effect of bismuth concentration on the structural and electronicproperties of the  GaAs1-yBiy solid solution is presented using the density functional theory in the VASP 5.4.4 software package. The results of the study showed that the fundamental band gap GaAs1-yBiy increase in the concentration of bismuth leads to an increase in the GaAs1-yBiy lattice constant, which causes internal asymmetry and a decrease in the Ga-Bi bond length. It has been shown that, with an increase in the number of Bi atoms substituting As atoms, a distortion of the position of neighboring Ga atoms and a decrease in the Ga-As bond length are observed at the sites of the crystal lattice. It has been established that these changes are due to the influence of the neighboring Bi atom, which affects the Ga-Bi bond length and reduces its length down to 2,6133 Å at y equal to 12,5%. The angle between the Ga-Bi and Ga-Bi bonds, on the contrary, increases with increasing Bi concentration and can reach a maximum value of 110,9256°. The combination of such structural changes in the crystal lattice of GaAs1-yBiy further lead to the emergence of potential defects in the form of clustering of Bi atoms or displacement of the Bi atom in the position of the interstitium. It has been established that supercells have the most stable configuration. GaAs1-yBiy with a concentration of Bi atoms up to 12,5%. The band gap of the GaAs1-yBiy solid solution decreases from 1,283 eV to 0,712 eV with increasing bismuth concentration from 1,85 mol.% to 12,5 mol.%. The band gap values obtained are, on the whole, close to known literature data. This shows that the direct band gap of this alloy covers the spectral region from the near infrared to the infrared range.
Keywords: III-V-Bi, GaAs1-yBiy, electronic structure, density functional theory, band gap.

Kartashynska E.S.
Conformation peculiarities of gemini surfactant monomers for 2D monolayer formation at the liquid/fluid interface – page 412
Abstract: The present work is devoted to the consideration of gemini surfactant monomers with a nonionic hydrophilic part and a different structure of the spacer connecting the hydrocarbon chains. It is possible to single out two conditional conformations of monomers depending on the spacer type: with an «extended» and «compact» spacer in the case of a flexible etoxylated or hydrocarbon chain, and only with the «extended» rigid spacer in the case of aromatic ring in it. The length for all three types of spacers in the case of their «extended» conformation is approximately the same for the considered bis-surfactants and allows two hydrocarbon molecules to be vertically introduced into the resulting cavity. The «compact» conformation of flexible spacers ensures the implementation of intramolecular CH‧‧‧HC interactions between hydrocarbon chains, which are not carried out in monomers with «extended» one. The thermodynamic parameters of formation for the found monomer conformations are calculated. For gemini surfactant conformers, the formation of structures with a «compact» spacer is more advantageous according to the Gibbs energy due to the formation of intramolecular CH‧‧‧HC interactions between hydrophobic chains of the amphiphilic compound. Comparison of the contributions of intramolecular CH‧‧‧HC interactions to the formation enthalpy and entropy of bis-surfactants with an etoxylated bridge in a «compact» conformation reveals good agreement with the similar contributions of intermolecular ones for dioxyethylated alcohols. It shows the same nature of CH‧‧‧HC interactionns realizing both inside a molecule with two hydrocarbon chains and between two surfactant molecules with single hydrocarbon chain.
Keywords: gemini surfactants, monomer, enthalpy, absolute entropy, Gibbs energy of formation, CH‧‧‧HC interactions.

Klychkov N.A., Kurmasheva D.V., Simakov V.V., Sinev I.V.
Mathematical modeling the polycrystalline layers conductivity of wide-bandgap semiconductors during adsorption on their surface of gases-reducers in the presence of oxygen – page 424
Abstract: The results of the response study of gas sensors based on gas-sensitive layers Cu:SnO2 toethanol, acetone, and  2-propanol vapors is are presented. Sensor response concentration dependencies are measured at different temperatures to determine optimal operating modes. Experimental temperature dependence of the sensors response to the vapors of the analyzed substances are determined. The dependence is theoretically substantiated by a proposed mathematical model based on consideration of the processes of transfer of charge carriers through the potential barrier grains of a polycrystalline semiconductor film in an oxygen-containing medium and the reducing gas to be analyzed. It is assumed that each type of gas on the surface of SnO2 has its own adsorption centers. The work shows that the model can be used to calculate and predict the gas sensitivity measurements of sensors based on the active layers of polycrystalline semiconductors. The results of the calculations confirm that such energy parameters as the depth of the energy level and the desorption energies are individual for each substance.
Keywords: organic matter vapor detection, semiconductor gas sensor, tin dioxide, temperature response dependency, dissociative adsorption.

Kolosov A.Yu., Savina K.G., Veresov S.A., Serov S.V., Sokolov D.N., Sdobnyakov N.Yu.
Scenarios of structure formation in four-component nanoparticles: atomistic simulation – page 432
Abstract: Scenarios of structure formation in four-component nanoparticles are considered. The objects of study were Au-Cu-Pd-Pt nanoparticles containing N = 400, 800, 1200, 1600, 2000, 4000 atoms of the stoichiometric composition Au3CuPd12Pt4. Two alternative modeling methods were used: the molecular dynamics and the Monte Carlo. The interaction between atoms was described by the tight binding potential. The phase transition temperatures for the nanoparticles under study were determined. It has been established that the melting and crystallization temperatures depend both on the size of nanoparticles and on the rate of temperature change (by using the molecular dynamics method). The melting rate of nanoparticles has little effect on the melting temperature, while increasing the cooling rate significantly reduces the crystallization temperature and slows down the segregation processes. The process of coalescence of two four-component nanoparticles was modeled. During the process of coalescence, significant mixing of atoms of different types does not occur when using the Monte Carlo method, which leads to some stopping of the growth of the neck at the point of contact, in contrast to molecular dynamics method, where the growth of the neck occurs gradually.
Keywords: molecular dynamics method, Monte Carlo method, tight-binding potential, four-component nanoparticles, structure formation, melting and crystallization temperatures.

Komarov P.V., Malyshev M.D.
Study of the effect of the ratio of epoxy resin and curing agent comonomers on mechanical properties of the system: mesoscale simulation – page 444
Abstract: This publication continues the cycle of our work aimed at improving the methodology for constructing mesoscale models of network polymers and characterizing their physical properties. As the object of study, the epoxy resin of bisphenol A, diglycidyl ether, and a tricarboxylic fatty acid hardener was chosen. Its structure is the result of three parallel reactions. For their correct reproduction, an algorithm was proposed, which allows to take into account the peculiarities of the relationship of all ongoing processes. The system model was constructed by mapping the chemical structure of the monomers onto an equivalent mesoscale representation. It was used to study the relationship between the structure and mechanical properties of feeding networks as a function of the ratio of volume fractions of comonomers in the initial reaction mixture. All calculations were performed within the reaction version of the dissipative particle dynamics method. The structure of polymer networks in the constructed samples was characterized by topological analysis. The study of mechanical properties was carried out by constructing the “stress-strain” dependencies. The results obtained show a good correlation between the density of the load-bearing chains and the mechanical properties of the resulting networks. It is shown that the material samples with the highest degree of transformation and the density of the number of load-bearing chains have the highest stiffness.
Keywords: network polymers, mesoscopic simulation, dissipative particle dynamics, mechanical properties.

Kotomkin A.V., Orlov Yu..D.
Quantum-mechanical calculation of the structural and energetic characteristics of the fluorinealcanes – page 456
Abstract: Within the «quantum theory of atoms in molecules» the charge q and volume V of topological atoms A and atomic groups R of fluorinated molecules of ethanes C2HmFk, where 0 ≤ m, k ≤ 6 and m+k = 6 and propanes C3HmFk, where 0 ≤ m, k ≤ 8, m+k = 8, has been calculated by Aimall software package. Optimization of the geometry and finding of the electron density distribution (ρ(r)) has been carried out by the GAUSSIAN 03 program with the B3LYP 6-311++G (3df,3pd) 6d 10f level of theory. Influence of fluorine atoms on near atomic groups has been studied. The absence of the transferable functional groups has been showed. A conclusion has been made about unsuitability of the evaluation of properties by additive methods, which do not consider differences in electron structures for this class of compounds. The enthalpy of formation ΔfH0 of 38 molecules of fluorethanes and fluorpropanes has been computed by the G4 method. The comparison with the experimental values has shown good coherence. Results of this work is planned to be used in designing additive models for prediction of thermodynamic and thermochemical properties of organic fluorinated compounds.
Keywords: inductive effect, electronegativity, electron structure, enthalpy of formation, quantum theory of atoms in molecules, electron density, fluorine alkanes, fluorethanes, fluorpropanes.

Kuznetsov Yu..A., Lapushkin M.N.
Ge adsorption on W(100): calculations – page 465
Abstract: For the first time, the adsorption of germanium atoms on the (100) face of tungsten was calculated using the density functional theory. The tungsten substrate was made as a 2D layer. The W2D layer was modeled by a W(100) 2×2×2 supercell. The calculation of the electron density of state and the adsorption energy of a Ge atom was carried out for three adsorption sites of the Ge atom: in the hollow position, in the bridge position between surface W atoms, and above the surface W atom: one Ge atom per 8 surface W atoms (most preferably adsorption of a germanium atom in hollow position). The adsorption energy is significant: 6,38 eV. The adsorption of Ge atoms leads to an insignificant reconstruction of the W surface: the maximum shift of W atoms does not exceed 0,15 Å. The valence band of the W(100) 2D layer is formed mainly by W 5d electrons, with an insignificant contribution of W 6s electrons. The Ge band is formed by Ge 4p electrons and Ge 4s electrons.
Keywords: adsorption, electronic structure, interface, germanium, tungsten.

Kurbanova E.D., Belyakova R.M., Polukhin V.A.
Micro and nanosized materials with high entropy – page 472
Abstract: The stability of high-entropy alloys, like equiatomic and non-equiatomic micro- and nanostructural ones, is relevant when creating stable multicomponent compositions with improved performance. The implementation of such materials is possible by mechanical alloying, magnetron sputtering, as well as by the electrochemical method using the «top-down and bottom-to-top» strategy at moderate temperatures < 200°C with controlled production of both micro-from 0,5 to 20 μm and nanoscale high-entropy alloys with particles from 2 to 10 nm. The well-studied «structure-property» relationship for classical alloys is not yet completely clear for nano-high-entropy alloys, but it is obvious that it is possible to form excellent mechanical characteristics by selecting chemical compositions and a special heat treatment regime. Regarding the chemical composition, requirements are imposed both on the main components and alloying additives. Preliminarily, not only compositions are selected, but also methods for the synthesis of high-entropy alloys, including ab initio (density functional theory), neural network prediction, and classical molecular dynamic simulation with possible conditions for the formation of model nano- high-entropy alloy samples, as well as derivative options. The resulting descriptions are compared with real methods of high-entropy alloys synthesis, for example, exposure to various synthetic media.
Keywords: multicomponent, amorphous and nanocrystalline alloys, high-entropy alloys, nano- highentropy alloys, strain hardening, landscape-local fluctuations, strength, thermal stability, layered composites, thermodynamic calculations.

Malysheva N.E., Dyakova E.V., Malyshkina O.V.
Simulation of the dielectric response of piezoelectric ceramics – page 481
Abstract: We have analyzed the complex permittivity of a porous (10 volume % of pores) sodiumlithium niobate ceramic with the results of computer simulation. The calculation was based on the Cole–Cole formula, which took into account the presence of various mechanisms of relaxation processes in the low-frequency (linear dispersion) and mid-frequency regions, an additional term from the Debye formula was added to take into account the mixed polarization, and a term taking into account the damping factor was added for resonant-type polarization. The simulation was carried out with and without the conductivity taken into account. To take into account the contribution of conductivity to the dynamic dielectric response, the expression σ* = (ε″ + iε′)ε0ω was used. It is shown that the linear part of the frequency dependence in the range from 50 Hz to 1 MHz is equally well described both with and without conductivity. At the same time, the behavior of the dielectric response of piezoelectric ceramics in the high-frequency region, where resonance effects are observed, and the low-frequency region, where volume-charge polarization predominates, is much better described taking into account the contribution of conductivity to the dielectric response of the system.
Keywords: piezoelectric ceramics, complex permittivity, complex conductivity, dielectric spectroscopy.

Myasnichenko V.S., Ershov P.M., Veresov S.A., Bazulev A.N., Sdobnyakov N.Yu.
Size effect and structural transformations in ternar nanoparticles Tix-Al96-x-V4 – page 495
Abstract: The final configurations obtained during crystallization in ternary metal nanoalloys Tix-Al96-x-V4 of various compositions were studied. The molecular dynamics method was used as an atomistic simulation method. Interatomic interaction was described by the tight-binding potential. The size dependence of melting temperatures, as well as changes in melting and crystallization temperatures with changes in the composition of ternary nanoparticles, have been determined. Based on the results of a series of computer experiments, differences in the crystallization scenarios of Tix-Al96-x-V4 ternary nanoparticles were established. A classification based on internal structure and degree of crystallinity was proposed and tested. For Tix-Al96-x-V4 ternary nanoparticles, five main classes are identified based on the number of (semi) axes of 5th order symmetry. Despite the fact that studying the segregation of components of Tix-Al96-x-V4 ternary nanoparticles was not the goal of the work, atomic configurations corresponding to different temperatures during the cooling process were constructed and described.
Keywords: molecular dynamics method, tight-binding potential, ternary nanoparticles, structure formation, melting and crystallization temperatures.

Nepsha N.I., Sokolov D.N., Mitinev E.S., Taktarov A.A., Sdobnyakov N.Yu.
Scenarios of structure formation in ternar nanoparticles based on Pd-Pt in the presence of dopant Ni – page 507
Abstract: In this work, scenarios of structure formation in ternary nanoparticles based on platinum and palladium of four stoichiometric compositions of different sizes were studied, with nickel acting as a dopant. Two alternative methods were used: the molecular dynamics method (implemented in the open source software LAMMPS) and the Monte Carlo method (implemented in the Metropolis scheme). In addition, to describe the interatomic interaction, two versions of force fields were used: the modified tightbinding potential (when implementing the molecular dynamics and Monte Carlo methods) and the embedded atom potential (when implementing the molecular dynamics method). Based on the results of a series of computer experiments, it was found that palladium atoms have increased segregation to the surface. At a cooling rate of 0,1 K/ps, an ordered crystalline FCC structure with inclusions of the HCP phase is formed. With an increase in the nickel dopant content to 20% in the ternary Pd-Pt-Ni nanoparticle, the identifiable local structure becomes more complex, both in terms of the number of phases and in terms of structural segregation.
Keywords: molecular dynamics method, Monte Carlo method, embedded atom potential, modified tightbinding potential, polyhedral template matching method, bimetallic and ternary nanoparticles, nickel, palladium, platinum, structure formation, melting and crystallization temperatures.

Polukhin V.A., Estemirova S. Kh., Kurbanova E.D., Belyakova R.M.
Nanosized high-entropic materials based on HEA, design principles and synthesis methods – page 520
Abstract: The principles of designing high-entropy alloys related to the selection of elements areanalyzed. When selecting elements, a parametric approach is used, including chemical and topological parameters. The main chemical parameter is the enthalpy of mixing of elements, the main topological parameter is the atomic radius. It is emphasized that the use of modified atomic radii (which take into account the local electronic environment) better predicts the formation of either amorphous or crystalline high-entropy alloys. Four main effects that determine the properties of high-entropy alloys are considered: the high entropy effect, the lattice distortion effect, the delayed diffusion effect, and the «cocktail» effect. Obtaining nanosized high-entropy materials based on high-entropy alloys is a new promising direction that allows one to significantly expand their areas of application related to energy (catalysis, energy storage, etc.), nanoelectronics, etc. The article analyzes some methods for the synthesis of nanosized high-entropy alloys and materials based on them. basis, developed as catalysts. The improved performance over conventional catalysts is explained in terms of the effects and features specific to multicomponent systems.
Keywords: multicomponent, amorphous and nanocrystalline alloys, high-entropy alloys and nanosized high-entropy alloys, morphology, catalysts, fcc and hcp structures, bcc, strength, thermal stability.

Ryzhkova D.A.
Phase-change memory cells based on nanoparticles alloy Ag-Au – page 536
Abstract: Phase-change random access memory is an excellent candidate for next-generation nonvolatile memory technology. In order to meet the needs of the industry, its capacity must be improved, for which it is necessary to reduce the volume of a unit cell. Proceeding from this, in this work, the possibility of using nanoparticles of the Ag-Au binary alloy as individual phase-change random access memory cells was evaluated by computer simulation. The method of molecular dynamics with a modified tight binding potential was used. For this, an analysis was made of the crystallization processes of these nanoparticles with a diameter of 2,0 to 8,0 nm with different rates of thermal energy removal. It was shown that the addition of gold to the composition makes it possible to solve the problem of the complex reproduction of the amorphous structure, which is characteristic of pure Ag nanoparticles. Due to this, stable switching between the amorphous and crystalline phases can be achieved at a nanocluster diameter of ≥4 nm and ≥6 nm with an Au content in the composition of ≥40% and ≥20%, respectively, which is significantly lower than the cut-off value of 10 nm characteristic of silver nanoparticles.
Keywords: nanoclusters, silver, gold, crystallization, structure, computer simulation, tight-binding, PCM cell.

Savina K.G., Grigoryev R.E., Veselov A.D., Bogdanov S.S., Ershov P.M., Veresov S.A., Zorin D.R., Myasnichenko V.S., Sdobnyakov N.Yu.
The problem of obtaining crystaline phases during cooling binary nanoparticles Au-Co and Ti-V – page 543
Abstract: The processes of structure formation in Co-Au and Ti-V metal nanoparticles as well as factors affecting the crystallization process are considered. The objects of the study were Co-Au and Ti-V binary nanoparticles containing N = 400, 800, 1520 and 5000 atoms with the equiatomic composition. The computer experiment was carried out using method of molecular dynamics. The interatomic interaction was described by the tight-binding potential. According to the results of a series of computer experiments, it was found that the main factors influencing the possibility of obtaining crystalline phases are: the cooling rate of binary nanoparticles, their size and the size mismatch of atoms included in the composition, as well as the nature of the interaction of metal atoms. The manifestation of stability/instability in binary nanoparticles may be due to patterns of formation of crystalline phases. Moreover, the tendency to segregate one of the components in a binary system may not be the main factor determining the stability/instability of such a system.
Keywords: molecular dynamics method, tight binding potential, binary nanoparticles, cobalt, gold, titanium, vanadium, dimensional mismatch, crystallization.

Samsonov V.M., Talyzin I.V., Vasilyev S.A., Puitov V.V.
Surface melting in nanoparticles and nanosystems. 1. Regularities and mechanisms of surface melting of macroscopic phases and nanoparticles – page 554
Abstract: Being the first part of a two-part series, published in this issue of the journal, this paper combines a brief overview of theoretical and experimental studies, as well as the results of atomistic simulations of surface melting in bulk bodies and nanoparticles with presentation of our own molecular dynamics results. We have studied the patterns and mechanisms of surface melting in metal nanoparticles (gold, silver, copper, lead and nickel). The patterns and mechanisms of this phenomenon were studied in most detail on gold and silver nanoparticles. It has been established that the effect of surface premelting is characteristic for nanoparticles of all the above metals, although with decreasing particle size this effect manifests itself to a lesser extent. In addition, our molecular dynamics results do not confirm theoretical predictions of some authors about the existence of a quite definite characteristic (critical) radius of nanoparticles, below which the effect of surface melting is completely absent.
Keywords: surface melting (premelting), metal nanoparticles, molecular dynamics, embedded atom method, LAMMPS.

Samsonov V.V., Vasilyev S.A., Talyzin I.V., Puitov V.V.
Surface melting in nanoparticles and nanosystems. 2. Scientific and nanotechnological aspects of the role of surface melting in nanoparticles and nanosystems – page 571
Abstract: Taking into account results of our molecular dynamics experiments, we have concluded thatof the three  commonly considered alternative models of nanoparticle melting (homogeneous melting, liquid shell, nucleation of liquid and growth), the latter is the most adequate. At the same time, a more adequate model corresponds to a combination of continuous melting at the initial stage of the process with its subsequent abrupt completion. In other words, nucleation and growth of a liquid-like surface layer occur until a certain critical radius of the crystalline core of the particle is reached, and then melting is completed very quickly, almost abruptly (in fractions of a nanosecond) at a temperature interpreted as the nanoparticle melting temperature Tm. Then, the role of surface melting in nanoparticle sintering is discussed. According to our results, the sintering of metal nanoparticles at high temperatures cannot be reduced to a single mechanism: a certain role play surface melting, surface and bulk diffusion, deformation in the contact zone, and collective effects associated with the displacements of groups (clusters) of atoms rather than of individual atoms. We also have put forward and substantiated the hypothesis that the previously introduced redetermined Tamman temperature TT=0,5Tm corresponds to the switching of the scenario of sintering of metal nanoparticles from formation of a dumbbell-shaped nanocrystal at low temperatures to the scenario corresponding to coalescence of solid nanoparticles resulting in the formation of a defective nanocrystal of a shape close to spherical.
Keywords: surface melting, metal nanoparticles, melting mechanisms, coalescence and sintering, molecular dynamics, thermodynamics.

Sdobnyakov N.Yu., Kolosov A.Yu., Sokolov D.N., Savina K.G., Bazulev A.N., Veresov S.A., Serov S.V.
Complex approach to the simulation of melting and crystallization in five-component metallic nanoparticles: molecular dynamics and the Monte Carlo method – page 589
Abstract: The melting and crystallization phase transitions in the five-component metallic Au-Ag-Cu-Pd-Pt equiatomic nanosystem were investigated. The complex approach to atomistic modeling is due to the use of alternative methods of computer simulation – the molecular dynamics and Monte Carlo methods. The interatomic interactions were described by the tight-binding potential. According to the results of a series of computer experiments, it was established that five-component nanoparticles of equiatomic composition can form crystalline phases during cooling. Melting and crystallization temperatures for the investigated five-component nanoparticles were determined. The values obtained by alternative methods are in good agreement. For five-component nanoparticles, the concept of fixing the temperatures corresponding to the beginning and end of the phase transition process is confirmed. The metals that make up five-component nanoparticles, the atoms of which in the process of crystallization form the central part of the nanoparticle (core) and the peripheral regions, including the surface of the nanoparticle, are determined.
Keywords: molecular dynamics method, Monte Carlo method, tight binding potential, five-component nanoparticles, structure formation, melting point, crystallization temperature.

Sokolov D.N., Polev O.V., Myasnichenko V.S., Savina K.G., Sdobnyakov N.Yu.
On the structural stability of mono- and binary metallic nanocages – page 602
Abstract: This work is devoted to the problem of thermal stability of mono- and binary metal nanocages consisting of gold and silver atoms. The number of atoms in the studied nanocages was 1744, 2150, 2470 and 3370 atoms. The characteristic size (outer diameter) of nanocages is from 4,4 to 5,1 nm. Interatomic interaction was described by the tight-binding potential. Analysis of the caloric dependences of the specific potential part of the internal energy made it possible to identify the temperature regions of «healing» of cavities (pores) on the faces and in the internal regions (cores) of nanocages. An example of the structural collapse of a nanocage is described in detail, as a result of which crystalline and quasicrystalline phases are identified in the nanoparticle core for a temperature corresponding to melting for the chosen size. Segregation in a binary Au-Ag nanocage before and after its collapse was also studied.
Keywords: atomistic simulation, tight binding potential, metallic nanocages, porеs, thermal effects, stability/instability, structure formation.

Cherepovskaya A.A., Ryzhkova D.A.
Computer simulation of structuring Ag-Cu nanoparticles – page 614
Abstract: In this work, computer simulation of the processes of formation of the internal structure of plasmonic Ag-Cu nanoparticles was carried out. Method of molecular dynamics based on the tight binding potential was used. The crystallization of Ag-Cu nanoparticles with a diameter of 2,0-8,0 nm with an atomic copper content ranging from 10 to 50% was simulated. To remove thermal energy, an Andersen thermostat was used with three different cooling rates ΔT/Δt = 30∙1011, 12∙1011, 5∙1011 K/s. The possible structural transitions arising in this case were determined using the radial distribution function and the change in potential energy. To determine the most stable cluster structure, an ensemble of nanoparticles of the same size was taken. Then, using the visualizers OVITO and xmakemol, the real appearance and structure of the studied nanoparticles were found. In the course of the simulation, it was found that at low levels of copper doping in Ag-Cu nanoparticles, the formation of five-particle symmetry is possible. The conditions for the occurrence of this effect were fixed. It was also determined that D = 8,0 nm for Ag-Cu nanoparticles is the size limit, starting from which the macroscopic effect of stabilizing the fcc structure of the eutectic alloy appears under the condition of very fast sample quenching.
Keywords: nanoclusters, silver, copper, crystallization, structure, computer simulation, tight binding.

4. PHYSICAL AND CHEMICAL BASES OF NANOTECHNOLOGIES – page 622

Ataeva A.Yu.
Dependence of the displacement of nanoparticles on channels in a jet bubbler – page 622
Abstract: The work is devoted to an experimental study of the behavior of bubbles when capturing pulverized materials with nanoparticles in the course of colliding of gas-liquid jets in a bubbling layer. The article discusses the use of channels in a jet bubbler and the dependence for detecting horizontal movement of bubbles with nanoparticles in them. The purpose of this stage of research is to study the behavior of gas-liquid jets when exiting without a guide channel and through a guide channel. The results of experiments conducted on the patented design of the jet bubbler are analyzed. The article presents the results of experiments conducted to study the shapes and sizes of formed gas bubbles. The graphs constructed after processing the frames of the kinogram according to the data of the experiments are given. On the basis of preliminary tests, the features of using channels to create the jet collisions in an experimental setup to increase the range of captured solid particles, including nanoparticles, are substantiated.
Keywords: ecosystem, dust and gas separator, nanoparticles, channel, wet dust collection, bubbling.

Belov A.N., Vostrov N.V., Pestov G.N., Solnyshkin A.V.
Features of the formation of an array of isolated polymer P(VDF-TrFE) nanoparticles in pores of a periodic nanostructured silicon oxide membrane – page 629
Abstract: This work is devoted to the technological features of creating an array of pyroelectric nanoparticles placed in the pores of a silicon oxide membrane, ensuring their thermal insulation both from each other and from the supporting substrate. Mechanisms of anodic oxidation of the Al/Ti/SiOstructure, ensuring the self-organization of a nanostructured oxide mask with specified geometric parameters, have been established. It has been shown that from a certain thickness of the adhesion layer, overgrowing of the open areas of the mask with titanium oxide nanoparticles does not occur. The regularities of the method of local ion etching of multilayer structures are determined, which ensures control of the depth of the formed pores by controlling the ion current. A correlation has been established between the lateral size of the cavities in silicon and the aspect ratio of aluminum oxide pores. The possibility of forming a silicon oxide membrane with pyroelectric polymer nanoparticles embedded in its pores has been demonstrated.
Keywords: polymeric ferroelectric, porous silicon oxide, ion-beam etching, IR – photodetector ,porous anodic alumina, micromembrane, anisotropic etching.

Belov A.N., Vostrov N.V., Pestov G.N., Solnyshkin A.V.
Planar jet printing of localized Ni/P(VDF-TrFE)/Ni structures for piezo- and pyroelectric matrixes – page 637
Abstract: This paper describes manufacturing the film structures based on a polar copolymer of poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) using the process of drop-by-drop local deposition on metallized substrates. The produced samples were a crossbar structures of arrays of ferroelectric P(VDF-TrFE) microislands metallized with nickel stripes using a combined 2D printing method. For the polymer layer deposition, a number of solvents with different viscosities and dipole moments of molecules were considered, and their influence on the geometry and the polar properties of printed layers was shown. Using the piezoelectric force microscopy, the value of the piezoelectric modulus of d33 at the nanoscale level was determined. This d33 modulus is similar to values of d33 for P(VDF-TrFE) films produced by the standard solvent cast method. On the base of amplitude of the pyroelectric current in the dynamic method, the value of the pyroelectric coefficient (p) was determined, varying from 2⋅10–5 to 4⋅10–5 C/(m2⋅K). These values are comparable to the pyroelectric coefficient of films P (VDF-TrFE) produced by the standard method. The highest values of d33 and p correspond to structures produced from solutions containing more than 20% of propylene carbonate in the initial solvent, the molecules of which have a large (4,9 D) dipole moment.
Keywords: .

Bogdanova E.A., Skachkov V.M.
Study of the possibility of obtaining biocomosites based on nanoscale hydroxyapatite with metals and biogenic elements – page 649
Abstract: The article discusses the possibility of obtaining a hardened composite material with a porous structure based on nanostructured hydroxyapatite (HAP) synthesized by precipitation from a solution. The new material by the mechanochemical synthesis of hydroxyapatite with aluminum, silicon, nickel, hafnium and titanium was obtained. The synthesized samples are certified using modern physico-chemical methods of analysis. The influence of the qualitative and quantitative composition of the composite on the sintering processes and the strength characteristics of the studied samples is shown. It has been experimentally established that the system Ca10(PO4)6(OH)2 – Ti is the most promising for the development of biocomposites based on it. Composite materials of this composition with the content of the doping component (10-20 wt.%), have a dense uniform structure with a high degree of crystallinity, with developed porosity, are a promising material for further research in order to introduce it into medical practice. A patent application has been filed for the developed composite material.
Keywords: hydroxyapatite, titanium, sintering, composite biomaterials, crystallinity, microhardness.

Bogdanova E.A., Khonina T.G., Sabirzyanov N.A.
Investigation of transport properties hydroxyapatite and its derivatives – page 659
Abstract: The article discusses the possibility of practical application of hydroxyapatite and fluorapatite as components of medicines, pharmaceutical compositions and biomaterials, the use of which is based on the transdermal delivery route of the active substance. The viscosity, density, degree of dispersion and transport properties (transmucose permeability) of hydroxyapatite and fluorapatite were estimated using modern physicochemical methods of analysis. Particular attention is paid to the joint use of the studied substances and silicon glycerolates as a conductor with pronounced transcutaneous, penetrating properties, contributing to the accumulation of locally applied drugs in biological membranes (skin, mucosa, etc.) without disturbing its structure. It is shown that the transport properties that determine the effectiveness of the action depend on the physico-chemical characteristics of the substances being penetrated. Diffusion transfer and the ability to control the processes taking place can be used for optimal design of drugs for targeted delivery through the skin and mucous membranes.
Keywords: hydroxyapatite, fluorsubstituted hydroxyapatite; siliconglycerolatas; transmucosal permeability.

Bolotov A.N., Novikova O.O.
Experimental study of the fluidity of nanostructured magnetic fluid in a strong magnetic field – page 670
Abstract: In this paper, we studied the changes in the topography of the surface of a unit made of magnetostrictive magnetoplast under the influence of a magnetic field. Theoretical analysis has shown that in composite materials when using magnetostrictive particles with a dispersion of 10-4÷10-6 m, a change in the surface roughness parameters is possible in the range of 10-7÷10-9 m, depending on the magnetostrictive constants of the filler. Local changes in the topography of the magnetoplast surface in a magnetic field with a strength of about 560 kA/m are experimentally determined, and an assessment is made of the integral changes characterizing the surface as a whole. For the experiment, a composite material containing a powder of TeFe2 material with a uniquely high linear magnetostriction (λs = 2∙103) was chosen. It has been established that the effect of the surface nanoroughness changing is especially pronounced for relatively smooth surfaces and depends on the composition, concentration, size, and orientation of the microfine magnetic filler. For the studied surfaces of magnetoplasts, the change in the height parameters of roughness exceeds 5%. In absolute terms, the change in the topography of the surface is tens of nanometers. In precision engineering, the detected effect can be used to control frictional characteristics, in particular, to change the friction force without contact, control the flow of small doses of various reactive gases, and change the dynamics of wetting processes of solid surfaces.
Keywords: magnetostriction, magnetoplast, magnetic field, surface topography, surface roughness, composite material.

Bolotov A.N., Afanasieva L.E., Meshkov V.V.
Lubricant properties of nanodisperse magnetic oils based on novel technical liquids – page 679
Abstract: The paper presents the results of studying properties of magnetic lubricating oils synthesized on the basis of fluoroorganic fluids and triethanol. The lubricating properties of oils were determined in the boundary friction mode under medium and high contact pressures. It is shown that magnetic oils based on perfluoropolyether have higher lubricating properties than oils based on other fluids, especially in the medium load range. The anti-wear properties and aggregative stability of oil begin to deteriorate sharply at temperatures exceeding 150°С. The use of perfluoropolyether liquid as an additive to oil made it possible to improve the antiwear properties of magnetic oil at medium and high contact pressures. The lubricating properties of magnetic oils based on triethanolamine are approximately the same as those of magnetic oils based on siloxanes, but worse than those of traditional non-magnetic oils. In terms of tribological properties, the studied magnetic oils are comparable to traditional plastic and liquid lubricants. The fact that magnetic oils have magnetic properties that are anomalous for liquids expands the area of their effective application significantly.
Keywords: magnetic lubricating oil, fluoroorganic liquids, triethanolamine, nanodisperse particles, friction, wear.

Bolotov A.N., Novikova O.O.
Experimental study of the fluidity of nanostructured magnetic fluid in a strong magnetic field – page 692
Abstract: Based on magnetic fluids, new effective technical devices have been implemented, such as magnetic fluid bearings, seals, and dampers. The magnetic-viscous effect inherent to magnetic fluids can not only improve the properties of magnetic fluid units, but significantly complicate their operation after a long stop. This refers to the so-called «stop effect», which occurs due to an abnormally high limiting shear stress in a nanostructured liquid. The plastic properties of the magnetic fluid are experimentally studied depending on the following parameters: shear stress, temperature, structure formation time. The destruction of the nanostructure of the magnetic fluid begins after the shear stress exceeds a certain critical value. At stresses below the critical, but above the limiting shear stress, the displacement of the solid surface occurs by overcoming the boundary friction of the magnetic fluid on the solid surface. The experimentally established exponential course of the temperature dependence of the shear rate reflects the nature of the forces that determine the internal friction in the magnetic fluid.
Keywords: magnetic fluid, yield strength, nanodispersed particles, magnetic interaction, chain model.

Gorshkov A.I., Gribanov E.N.
Features of the mechanism of formation of morphology of aluminosilicate films on aluminum substrate – page 701
Abstract: The features of the formation of morphology of thin aluminosilicate films obtained electrochemically on an aluminum substrate from aqueous solutions of sodium silicate and sodium hydroxide have been systematically studied by atomic force microscopy. The effect of stress on the shape and characteristic dimensions of the surface elements of aluminosilicate films is shown. Films synthesized at a lower voltage (8 V) are characterized by an amorphous surface consisting of globules whose size ranges from 500 nm to 2,5 microns, for samples obtained at a higher voltage (more than 16 V), parallelepipeds with linear dimensions of 150-250 nm act as are found to be structural elements. It is established that at the first stage of synthesis, the surface of the aluminum anode is etched, and the resulting cells act as pores in which the aluminosilicate phase is formed. An assumption is made about the formation of films along the path of autocatalytic nucleation and about a direct dependence of the rate of formation of the crystalline phase on the voltage at which the synthesis is carried out.
Keywords: synthetic aluminosilicates, growth mechanism, thin films, surface morphology, electrochemical synthesis.

Doroshenko A.E., Krut’ko V.K., Musskaya O.N., Dovnar A.I., Ostrowskaya O.B., Doroshenko Ye..M., Kulak A.I.
Phase composition and biocompatibility of calcium phosphate coatings on titanium enriched with hydroxyapatite – page 708
Abstract: Calcium phosphate coatings containing brushite, calcite, and apatite were obtained by electrochemical deposition on titanium plates at room temperature, pH 5, constant current density 30 mA/cm2, from CaCO3/Ca(H2PO4)2 suspension electrolyte. A layer of amorphous apatite was deposited by the biomimetic method, by keeping the coatings in a concentrated modeling solution of Simulated Body Fluid. As a result of heat treatment at 800°C, apatite crystallized into hydroxyapatite, calcite decomposed to calcium oxide, and titanium was covered with a layer of titanium (IV) oxide. Preclinical studies on rats in vivo for 3 months showed increased osseointegration of plates with calcium phosphate coatings compared to uncoated titanium. Titanium implants with calcium phosphate coatings enriched with hydroxyapatite are promising for use in neurosurgery, dentistry, orthopedics due to the absence of inflammatory reactions from the body and increased osseointegration.
Keywords: calcium phosphate coatings, brushite, calcite, SBF model solution, apatite, hydroxyapatite.

Zajogin A.P., Trinh N.H., Patapovich M.P.
Influence of the defocusing parameter of dual laser pulses on the possibility of designing thin-film cassensitive sensors – page 718
Abstract: The possibility was studied of creating thin-film gas-sensitive sensors using composite materials containing tin in their composition, which can significantly improve their characteristic. In addition, a layer-by-layer analysis of metals and multicomponent alloys was carried out under the action of dual laser pulses on a target in an air atmosphere. All experiments were carried out using a laser two-pulses multichannel atomic emission spectrometer LSS-1. In the course of this study, the processes of formation of a certain component composition of the near-surface laser plasma, as well as the influence of the defocusing parameter between doubled laser pulses upon their impact on the surface of the irradiated sample, were studied. Thus, this work illustrated the development of methods for obtaining nanoclusters of chemical elements during spectroscopic studies of laser plasma formed by the action of two successive pulses on a target and the possibility of obtaining nanofilms of both pure metals and composite alloys for subsequent practical application.
Keywords: gas-sensitive sensors, double laser pulses, laser plasma, layer-by-layer analysis, deposition of thin films, multichannel atomic emission spectrometry..

Ivanov Yu.F., Klopotov A.A., Shugurov V.V., Azhazha I.I., Petrikova E.A., Tolkachev O.S., Nikonenko A.V.
Amorphous-crystalline boron-containing coatings formed by the ion-plasma – page 725
Abstract: Using the method of high-frequency ion-plasma sputtering (magnetron highfrequency deposition under conditions of ion-plasma assisted using a gas (argon) plasma generator «PINK») on the surface of a high-entropy CoFeCrMnNi alloy of non-equiatomic composition. Boron-containing coatings of the elemental composition Al – Mg – B and Mg – Ti – B with a thickness of 3 μm are formed. Using transmission electron diffraction microscopy, it was found that the coatings are amorphous-crystalline, i.e. contain nanosized 1.5-2 nm islands of the crystalline phase located in an amorphous matrix. It is shown that the coating deposition is accompanied by the formation in the substrate layer (high-entropy alloy) adjacent to the coating of a nanocrystalline structure with a crystallite size of 25-40 nm. At the boundaries of the crystallites, particles of iron boride of the FeB and Fe3B compositions are revealed, which indicate the penetration of boron into the substrate. The particle size of iron boride is 5-8 nm.
Keywords: ion-plasma method, high-entropy alloy, film/substrate systems, boron-containing coating, structure, mechanical and tribological properties.

Kislova I.L., Malyshkina O.V., Ivanova P.A., Ivanova A.I.
Production of barium-calcium-strontium niobate ceramics with optimal properties for practical application – page 736
Abstract: In this work, we obtained at various sintering temperatures and studied the ceramic samples of a 3-component system of barium niobate – calcium – strontium (Ca0,28Ba0,72)0,25(Sr0,61Ba0,39)0,75Nb2O(CSBN25) which is a nanostructured solid solution. The effect of sintering temperature on the structure and dielectric properties of CSBN25 ceramics was studied. It has been established that the CSBN25 sample obtained at a sintering temperature of 1300°С has the optimal ferroelectric properties. For this sample, the pore size does not exceed 10 – 100 nm, while for samples sintered at other temperatures, pores can reach 10 microns. Using examples of CSBN25 ceramics, we have also shown a direct relationship between the uniformity of the grain structure and their packing density with the dielectric properties of the samples: the maximum density and the value of the permittivity have the samples that have a dense, uniform grain structure not only on the surface, but also in the bulk of the samples. Increasing the sintering temperature of CSBN25 ceramics to1350°С leads to the appearance of an amorphous state in the sample bulk and, as a result, to a decrease in the dielectric constant.
Keywords: piezoelectric ceramics, barium – calcium – strontium niobate, lead-free materials, grain structure, permittivity.

Klychkov N.A., Simakov V.V., Efanova V.V., Sinev I.V.
Cross effect of isopropanol and ethanol vapor on the response of a semiconductor gas sensor – page 746
Abstract: the temperature dependencies of the response of Cu:SnO2 films to ethanol, 2-propanol vapours, as well as ethanol with 3% vol. background impurities of 2-prophanol in the working temperature range of 250-375°C. The aim of the study was to determine the effect of the 2-propanol background impurities on the sensor response to ethanol, as well as to assess the possibility of distinguishing a steam-air mixture containing pure ethanol vapors from a gas mixture of ethanol/2-propanole by means of single-sensor signal statistical processing. The temperature dependencies analysis of the sensor response showed that the temperature at which the maximum response is observed is individual for each substance. A selective response to substances was detected. It was found that the 3% vol. isopropyl alcohol compound decreases the response to ethanol in the tested concentration and temperature range. Statistical processing of experimental data by the principal component analysis (PCA) and cross-validation of the model by the ellipsoid and nearest-neighbor showed the fundamental ability to recognize ethanol, 2-propanol and their mixture.
Keywords: semiconductor gas sensor, detection of gas mixture, tin dioxide, temperature dependence of response, principal component analysis.

Malashenko V.V., Malashenko T.I.
Effect of nanoscale defects on inelastic processes in aged alloys – page 754
Abstract: The high strain rate deformation of an aged alloy with a high concentration of GuinierPreston zones is theoretically analyzed. The analysis was carried out within the framework of the theory of dynamic interaction of defects. An analytical expression for the dependence of the dynamic yield strength on the concentration of impurity atoms has been obtained. The reasons of the different influence of Guinier-Preston zones on inelastic processes at different strain rates are analyzed. It is shown that under high strain rate deformation, nanosized defects affect the nature of the dependence of the dynamic yield stress on the concentration of impurity atoms. This dependence becomes nonmonotonic and has a minimum and a maximum. The maximum corresponds to the transition from the dominant influence of the collective interaction of dislocations on the spectral gap to the dominance of the influence of the collective interaction of impurity atoms. The minimum corresponds to the transition from dominance of dislocation drag by Guinier-Preston zones to dominance of drag by impurity atoms. Numerical estimates of the contribution of the Guinier-Preston zones to the yield strength are made. It is shown that at a high concentration of Guinier-Preston zones, this contribution is very significant. Numerical estimates are made of the concentration of impurity atoms, at which the concentration dependence has a maximum and a minimum.
Keywords: high strain rate deformation, dislocations, Guinier-Preston zones, point defects, nanomaterials.

Maraeva E.V., Permiakov N.V., Moshnikov V.A.
The features of application of eutectic melts based on indium and gallium – page 760
Abstract: In a brief review, the main trends in the use at the present time of eutectic melts based on indium and gallium (EGaIn) are considered. Examples of the use of EGaIn in transistors, capacitors, electrodes, and probe systems (including those in four-probe techniques) are given. The main properties of EGaIn and the spreading of a drop of EGaIn melts are considered, and a detailed scheme of the point-contact four-probe method is given. The main issues discussed in the application of EGaIn in the field of obtaining liquid electrodes, including the formation of gallium oxides, the possibility is revealed of the influence of the spatial environment on the EGaIn droplet and manipulation of microdroplets,. It has been established that among the works of 2022-2023, a large segment is occupied by publications in the field of flexible electronics, intelligent robots, as well as wearable devices (for example, the creation of a metatissue with an antibacterial effect and the ability to be heated with a low energy consumption) and biomedical applications (the development of smart gloves for manipulating gestures, measuring the heart rate of insects).
Keywords: eutectic melts, EGaIn, liquid probes, flexible electronics .

Molchanov S.V., Tretyakov S.A., Ivanov A.M., Kaplunov I.A.
Effect of optical processing on the surface structure of paratellurite single crystals – page 777
Abstract: The effect of optical treatment of the surfaces of a paratellurite single crystal corresponding to the (100), (110), and (001) crystallographic planes was studied. Using a NanoMap WLI1000 optical profilometer, the relief layer of the sample surface (paratellurite single crystal) was controlled. To study the influence of the polishing method, the process was carried out using three techniques – neutral polishing, acid polishing and alkaline polishing. The characteristics of paratellurite surfaces after grinding and polishing are determined. Conclusions are drawn about the predominant use of polishing with chemical reagents. The anisotropy of surfaces differing in crystallographic directions on the speed of grinding and polishing and on the characteristics of the surfaces is shown. Studies of the structure of ground and polished surfaces corresponding to crystallographic planes have shown that the maximum roughness height is observed for the (001) plane. The smoothest surface is achieved for surfaces coinciding with the crystallographic plane (110).
Keywords: paratellurite single crystals, optical surface, grinding, polishing, roughness.

Molchanov S.V., Tretyakov S.A., Kaplunov I.A., Ivanov A.M., Stepanov V.S., Tsvetkov V.P., Tsvetkov I.V., Mikheev S.A.
Micromorphology and fractal parameters of growth surfaces of single crystals of paratellurite – page 787
Abstract: This paper presents studies of the influence of growth conditions of paratellurite single crystals on the side surface of grown boules and the possibility of assessing the quality of crystals based on the values and dynamics of the roughness parameters and fractal parameters of juvenile surfaces. Two single crystals were grown under similar technological conditions and differing from each other in structural quality. Their lateral surfaces were studied using the optical interference profilometer NanoMap 1000WLI employing SPIP and Gwyddion softwares. As a result, roughness parameters of profiles, and fractal parameters of crystal surfaces along the growth direction were obtained,. It was concluded that under conditions corresponding to the formation of stable flows in the melt, the values of the surface roughness over the entire length of the crystal is less than 5 μm, and the fractal energy parameter can be used as a marker of the quality and homogeneity of crystals.
Keywords: paratellurite single crystals, untreated crystal surface, roughness parameters, fractal parameters.

Ostroushko A.A., Vylkov A.I., Zhulanova T.Yu., Russkikh O.V., Tonkushina M.O., Beketov I.V.
Influence of nanoscale additives on the sintering temperature of aluminum oxide – page 799
Abstract: As an initial sample of aluminum oxide, we used material of industrial production for the manufacture of ceramic products. Aluminum oxide powders were prepared as additives introduced into the basic material in an amount of 3% by mass obtained by electric wire explosion as well as in combustion reactions of nitrate-polymer precursor based on polyvinyl alcohol. The obtained additives were characterized in terms of the structure and particle morphology. The samples of the first type included a mixture of different modifications of aluminum oxide, the second type included hydrated aluminum oxide. The first two samples consisted mainly of unaggregated spherical nanoparticles with specific surface area of 20 and 69 m2/g, and the powder obtained in combustion reactions contained flat flake particles, it had a specific surface area of 8 m2/g. The introduction of nano-sized additives led to a shift of the dilatometric sintering curve of compacted samples to lower temperatures, up to 140 degrees maximum. The sample with the largest specific surface was more active in lowering the sintering temperature. The result obtained for the pyrolytically synthesized additive was comparable with the above-mentioned shift in the sintering curve.
Keywords: aluminum oxide, sintering, nanoscale additives, electric wire explosion method, nitratepolymer precursor combustion method.

Pan’kin N.A., Mishkin V.P.
Electronic microscopy of the surface of SCMnCr3 steel after electric spark treatment with a tungsten electrodeanode – page 807
Abstract: The method of scanning electron microscopy was used to study the surface morphology of steel SCMnCr3 after its electrospark treatment with a tungsten (without additives) anode electrode. The following structural elements have been identified: bulges, spherical and disk-shaped inclusions, cracks, pores and particles of irregular shape. Their appearance is due to high temperatures in the interelectrode gap (higher than the corresponding melting temperatures of the main electrode materials) and the non-equilibrium of the processes occurring in it. During the formation of pores, the main mechanism is the release of gases during cooling of the electrode materials in the liquid phase. Macrostresses arising from an electric spark discharge in the surface layers of the electrodes, which exceed the mechanical properties of the electrode materials, lead to the ejection of irregularly shaped solid particles into the interelectrode gap and the appearance of cracks. The appearance of sagging, round/oval inclusions, and spherical particles is associated with the interaction of the liquid phase from the interelectrode gap with the cathode surface.
Keywords: steel, tungsten, electrospark processing, morphology, electron microscopy.

Gafner Yu.Ya., Ryzhkova D.A.
Functioning features of the gas sensor based on SnO2 – page 814
Abstract: Every year modern industry increases the number of technological processes using highrisk chemicals. Therefore, for the uninterrupted work of personnel, it is necessary to minimize the possible consequences of leakage of these substances, but for this, first of all, a clear definition of the maximum permissible concentration of a particular hazardous substance in the air is required. In the last decade, nanomaterials of various types have been used as active elements for gas sensors, and gas sensors based on tin oxide have become the most popular among researchers. In this work, typical reactions of the interaction of the surface of a nanocompacted SnO2 layer with some detectable gases were studied. It is shown that with an increase in the concentration of the analyzed gas due to its chemical absorption, the electrons previously captured by oxygen are released, which leads to an increase in the number of nanoparticles in the conducting state. This feature makes it possible to use the nanocompacted SnO2 layer for the determination of nitrogen mono- and nitrogen dioxide in the atmosphere.
Keywords: absorption, semiconductors, nanocompacted material, gas sensors, simulation.

Skachkov V.M.
Properties of diffusion-hardening composite solder modified with vanadium powder – page 823
Abstract: The article considers the effect of vanadium metal powder on the properties of diffusionhardening solder  basedon a low-melting gallium-tin alloy and a solid component consisting of a copper-tin alloy powder. After the introduction of vanadium metal powder in the amount of 5, 10 and 15 wt.%, solder samples were subjected to heat treatment at two different temperatures – 125 and 600°C. The microhardness and thermal stability of composite diffusion-hardening solders are evaluated. It is shown that heat treatment at higher temperatures promotes the transition of solder to an equilibrium state, which leads to an increase in hardness due to the formation and distribution of intermetallic compounds, including nanoscale ones. The phases of vanadium intermetallides formed as a result of interaction with gallium were determined by X-ray phase analysis. Metallic vanadium is wetted by gallium, has limited solubility, and increases solder hardness due to precipitation strengthening.
Keywords: composite diffusion-hardening solders, metal powder, properties, microhardness, differential thermal analysis, vanadium.

Skachkov V.M., Pasechnik L.A., Medyankina I.S., Sabirzyanov N.A.
Changing the properties of diffusion-hardening solders hardened with titanium, zirconium, and hafnium powders – page 831
Abstract: This article presents the results of a study of the properties of three diffusion-hardening solders based on low-melting gallium alloys and copper-tin alloy powder after the introduction of inert metal powders of titanium, zirconium, and hafnium in an amount of 5% each, which is an additive of 15 wt.%. After heat treatment at low temperatures (125°C) in within 24 hours, and after hightemperature treatment (600°C) for 6 hours, the microhardness of the obtained composite diffusionhardening solders was evaluated. Relatively long-term heat treatment at low temperatures does not lead the composition to achieve equilibrium states, possible physico-chemical transformations do not fully occur in them, which shows an increase in the hardness of samples after high-temperature treatment. X-ray phase analysis has determined the phases formed as a result of diffusion hardening, forming micro- and nanoscale intermetallic compounds, and the metal tin released in the form of nanoscale secretions in the intergrain space. Metal filler powders, inert at low temperature to exposure, but well wetted with gallium at high temperatures, interact with it, forming nanoscale intermetallic compounds, additionally strengthening composite solders.
Keywords: composite diffusion-hardening solders, metal powder, titanium, zirconium, hafnium, properties, microhardness, differential thermal analysis.

Stolyarov V.V.
Tribological aspects of nanostructured materials – page 840
Abstract: The article is devoted to the review of structural factors influencing the tribological behavior of nanostructure metals and alloys without lubrication. The scientific significance of this topic is related to the understanding of wear mechanisms and the possibility of its prediction during long-term operation. Particular attention is focused on the effect of the grain size in the range of 0,01-10 µm, as one of the most important structural parameters. Emphasis is placed on materials with ultrafine grains obtained by severe plastic deformation, and nanocrystalline materials obtained by non-deformation methods of sputtering and deposition. It is shown that nanocrystalline films on the contact surface are more preferable for increasing wear resistance, since they are more resistant to structural-phase transformations during friction. Among pure metals, as objects without phase transformations, copper, nickel, aluminum and titanium are considered. As an example of more complex objects, alloys based on titanium (an intermetallic compound with shape memory TiNi and two phases Ti-Al-V alloy) are presented. In addition to the classical scheme of friction during macrodisplacement of the indenter on the contact surface, the fretting friction during microdisplacement is considered.
Keywords: slip, wear, friction coefficient, nanostructure, fretting, roughness.

Suliz K.V., Pervikov A.V.
Structural-phase states of the multicomponent alloy nanoparticles AlCuNiCoCrFe produced by of joint exploding wires – page 851
Abstract: In this work, for the first time, samples of nanoparticles of the multicomponent AlCuNiCoCrFe alloy were obtained by the method of joint electric explosion of wires of Al, Cu, Ni metals and N06003, NiCo29-18 alloys in an argon atmosphere. As the basic mode of wire explosion, a mode close to the matched one was chosen, which made it possible to minimize the influence of the energy of the arc stage of the discharge on the structural-phase state of the forming nanoparticles. It is shown that the obtained samples are represented by spherical particles with sizes ranging from 15 to 500 nm. The number-average size of nanoparticles of the obtained samples varies from 40 to 58 nm. The particle size distribution is described by a normal-logarithmic law, the crystal structure of the particles corresponds to substitutional solid solutions with a bcc and/or fcc lattice. An increase in the Al content in the explosion products leads to an increase in the content of the phase with a bcc lattice in the samples, while an increase in the Cu content leads to an increase in the phase with a fcc lattice. The resulting samples can be used in electrocatalysis.
Keywords: nanoparticles, high-entropy alloys, structural-phase state, electric explosion, current, voltage, powder.

Suliz K.V., Sdobnyakov N.Yu.., Pervikov A.V.
Structural-phase states of the multicomponent alloy nanoparticles CoMoFeNiCu produce by of joint exploding wires – page 861
Abstract: Using method of the joint electric explosion of wires of various metals/alloys, for the first time nanoparticles were obtained of a multicomponent alloy with high activity in the ammonia decomposition reaction. It is shown that the obtained samples are represented by spherical particles with an average size of about 40 nm. The crystal structure of nanoparticles contains fcc, bcc phases, as well as a phase corresponding to an intermetallic compound. Energy dispersive analysis data show that in the obtained samples two types of copper segregation in the of particles are observed: enrichment in the central region of the particles and segregation on the surface with formation of a structure characteristic of «Janus» particles. The data obtained indicate the need to involve atomistic modeling methods in the search for optimal quantitative compositions of nanoparticles of multicomponent alloys to provide the necessary desirable structure and functional properties. The prospects for applying atomistic simulation to high-entropy alloys are noted.
Keywords: nanoparticles, high-entropy alloys, exploding wires, catalysis, powder.

Tumarkina D.D., Butkovskii O.Ya., Bolachkov A.V., Burtsev A.A.
Surface topology of mixing entropy after two-pulse laser ablation of stainless steel – page 869
Abstract: The paper presents experiments on crystallization from a melt with an analysis of the morphology of the emerging crystal structures, showing examples of the formation of dendritic crystals. Using energy dispersive X-ray analysis, studies of the microelement analysis of the areas of effect of two pulsed laser beams on the surface of stainless steel have been carried out for irradiation parameters corresponding to the appearance of dendritic structures in the area of effect. It is shown that in the dendritic regions concentrations of all the components of AISI 304 stainless steel are equalized. Estimation of the entropy of mixing from experimental data showed that in the area of surface dendrites or their accumulations, the surface entropy of mixing corresponded to its value for a high-entropy alloy. Based on the maximum entropy production principle, the phase transition temperature was calculated. Although dendritic crystallization should reduce the entropy of the system, experiments show that the entropy of the alloy increases. Preliminarily it can be concluded that this process is associated with a high oxygen content in the region of dendritic crystal formation after laser irradiation. The results presented in this work allow us to conclude that the formation of structures with complex morphology occurs after thermal oxidative ablation.
Keywords: two-pulse laser ablation, dendritic crystals, high-entropy alloys, entropy of mixing, entropy conductivity.

Shomakhov Z.V., Nalimova S.S., Rybina A.A., Buzovkin S.S., Kalazhokov Z.Kh., Moshnikov V.A.
Improving the sensor characteristics of binary and ternary oxide nanosystems – page 879
Abstract: Currently, adsorption gas sensors are of great interest for environmental monitoring. The approaches to improving their properties include synthesis of nanostructured materials of various shapes and modification of the metal oxide chemical composition. The aim of this work is to develop ways to improve the sensor properties of zinc oxide nanowires by changing the surface structure during processing in solutions of tin and iron compounds, as well as adding special precursors during their synthesis. The layers consisting of zinc oxide nanowires were produced by hydrothermal method. Ternary Zn-Sn-O and Zn-Fe-O nanosystems were synthesized as a result of processing of zinc oxide nanowires in solutions containing potassium stannate and iron sulfate, respectively. ZnO nanowires were also synthesized in a solution containing sodium bromide in addition to the general precursors. The surface chemical composition was analyzed using X-ray photoelectron spectroscopy. Sensor properties were investigated by detecting acetone, isopropanol and methanol vapors. It was shown that the sensor response of the produced samples exceeds the response of the initial zinc oxide nanowires. The samples of Zn-Sn-O ternary oxide system have the best response. The improvement of the sensor response may be associated with an increase in the content of adsorbed oxygen ions on the surface of the samples, the presence of metal cations with different properties as well as the formation of heterostructures.
Keywords: gas sensors, metal oxides, nanomaterials, zinc oxide, X-ray photoelectron spectroscopy, adsorption centers.

5. NANOCHEMISTRY – page 888

Belov D.V., Belyaev S.N., Yunin P.A., Nazarov A.A.
Formation of copper clusters in the process of biocorrosion of aluminum alloys by microscopic fungi – page 888
Abstract: In this work, biocorrosion of D16T and AMg6 aluminum alloys under the influence of microscopic fungi was studied. It has been shown that micromycetes produce reactive oxygen species – superoxide anion-radical, hydrogen peroxide, which initiate biocorrosion of metals. The composition products of biocorrosion of D16T and AMg6 after exposure of the alloys on the lawn of a consortium of micromycetes was determined by energy-dispersive X-ray spectroscopy. An X-ray phase study of alloy biocorrosion products was carried out. Scanning electron microscopy and X-ray diffraction analysis show the formation of nanosized and submicron copper clusters. A physicochemical mechanism of biocorrosion of aluminum alloys by microscopic fungi is proposed. An assumption is made about the mechanism of operation of the «zerovalent metal – hydrogen peroxide» systems, which can trigger a cascade of reactions leading to the destructive oxidation of metals. The paper attempts to explain the role of microfungal community biofilms as the main factor in the mycological corrosion of metals.
Keywords: biocorrosion, microbiological corrosion, aluminum alloys D16T, AMg6, zerovalent aluminum, zerovalent copper, microscopic fungi, reactive oxygen species, superoxide anion radical, hydrogen peroxide, copper clusters.

Bibanaeva S.A., Bogdanova E.A., Skachkov V.M.
Synthesis and investigation of functional characteristics of composite materials based on nanoscale hydroxyapatite and synthetic zeolites – page 913
Abstract: The article discusses the possibility of obtaining composite materials based on nanostructured hydroxyapatite synthesized by precipitation from solution and synthetic zeolites by mechanochemical synthesis. The synthesized samples are certified using modern physico-chemical methods of analysis. The influence of the qualitative and quantitative composition of the composite and the temperature treatment modes on the sintering processes and the strength characteristics of the studied samples is showed. It has been experimentally established that the maximum strength characteristics and constant composition are possessed by a sample based on hydroxyapatite, the content of the reinforcing additive in which is 15 wt.%. It was also found that the hydroxyapatitezeolite composite exhibits sorption properties against heavy metal ions and fluorine ions. The studies carried out allow us to recommend the samples obtained for further research in order to introduce it into medical practice, but also as a sorption material for the extraction of ions from aqueous solutions.
Keywords: hydroxyapatite, synthetic zeolites, composite materials, microhardness, sorption.

Bibanaeva S.A., Skachkov V.M.
Sorption of heavy metals from aqueous solutions with synthetic zeolites – page 924
Abstract: The work is devoted to the study of the possibility of using synthetic aluminosilicate zeolites obtained from recycled solutions of alumina production by the hydro-alkaline method as sorbents of heavy metal ions (copper, zinc and iron), as well as fluorine and chlorine ions from slightly acidic aqueous solutions. Natural zeolite and graphite were used as comparison samples under the same conditions. The chemical qualitative and quantitative composition, morphology of the initial reagents and the resulting solutions were studied. It has been established that synthetic zeolite exhibits sorption properties with respect to heavy metal ions that exceed the indicators under the same conditions for comparison objects. Also, positive results were obtained during the sorption of chlorine and fluorine ions. The conducted studies allow us to recommend the obtained samples for further research in order to introduce it not only for the extraction of various ions from aqueous solutions, but also for use in various industries.
Keywords: wastewater treatment, synthetic zeolite, sorption, heavy metals, aluminosilicate.

Blinov A.V., Golik A.B., Gvozdenko A.A., Kastarnova E.S., Orobets V.A., Yakovenko A.A., Bakholdina T.N.
Development of a biologically active nanosystem based on riboflavin, a microelement of copper and L-lysine amino acid – page 930
Abstract: А biologically active nanosystem based on riboflavin, copper microelement and the amino acid lysine copper lysinatoriboflavinate has been developed. The obtained sample of the biologically active additive was studied by a complex of modern methods of analysis, namely: spectrophotometry, scanning electron microscopy, spectrophotoluminescence spectroscopy. In addition, computer quantum chemical modeling was carried out. It has been established that the most energetically favorable model of a biologically active nanosystem based on riboflavin, a trace element of copper and lysine is a model in which riboflavin is bound to the copper ion through the enol oxygen at C2 and the neighboring nitrogen heteroatom N3, and lysine is bound to the copper ion through the carboxyl and amino groups in α position. As a result of the analysis of micrographs of a biologically active nanosystem based on riboflavin, copper microelement and lysine amino acid, it was found that the particles have an acicular structure, the width of individual crystals is from 100 to 300 nm, and the length reaches several microns. The energy-dispersive X-ray spectra of a biologically active nanosystem based on riboflavin, the microelement copper, and the amino acid lysine coincide with the theoretical concepts of the structure of the elements under consideration. The analysis did not show the presence of impurity compounds, which may allow us to judge the high purity of the developed compound.
Keywords: trace element copper, essential amino acids, quantum chemical modeling, vitamin B2.

Blinova A.A., Kastarnova E.S., Pirogov M.A., Kuznetsov Ye..S., Leontiev P.S., Filippov D.D.
Determination of the optimal configuration of the molecular system «manganese silicate nanoparticles-an essential amino acid» – page 940
Abstract: In this study, the optimal configuration of the molecular system «manganese silicate nanoparticles – essential amino acid» was determined using quantum chemical simulation. To begin with, quantum chemical simulation of individual molecules of manganese silicate and essential amino acids was carried out, after which molecular systems «manganese silicate nanoparticles – essential amino acids» were modeled, in which an oxygen atom attached to silicon atom in manganese silicate was combined with an ionized amino group of amino acids. As a result, it was found that the molecular systems «manganese silicate nanoparticles – essential amino acids» are energetically advantageous and chemically stable. Based on the data obtained, it can be concluded that the optimal configuration of these molecular systems is the interaction of manganese silicate with lysine through the ionized α-amino group of lysine. This molecular system has the highest values of the difference in total energy (ΔE = 73.268 kcal/mol) and chemical hardness (η = 0.144 eV), which are indicators of energy benefits and chemical stability of molecular system. After mixing manganese acetate, L-lysine and sodium silicate, manganese silicate nanoparticles stabilized with L-lysine were obtained.
Keywords: manganese silicate nanoparticles, essential amino acids, quantum chemical modeling, lysine, IR spectroscopy.

Golovanova O.A., Kiselev V.M.
Mathematical modeling of formation of nanocrystalline calcium oxalate under physiological conditions – page 950
Abstract: For the first time, a physicochemical model of the formation of poorly soluble compounds in the kidney nephron was developed on the basis of a mathematical description of the ideal displacement reactor. As a result of mathematical modeling, it was found that under normal physiological conditions, the formation of a solid phase is not the dominant process, which explains the absence of crystalline formations in the kidneys in healthy people. An increase in the concentration of precipitate-forming ions, corresponding to certain conditions of the human body, leads to the occurrence of local high supersaturations in certain areas of the nephron, which can lead to the formation of solid phase nuclei, their fixation and further growth. It is shown that the calculations of material balances, flow movements, as well as the concentration profiles of components in the nephron determine the possibility of predicting the behavior of the model system with variations in the parameters and conditions that affect the course of the crystallization process (concentration, fluid flow, hydrodynamic regime, etc.), which will allow developing effective methods for the prevention and treatment of urolithiasis, including the dissolution of already formed aggregates.
Keywords: crystallization, calcium oxalates, saline, model, plug flow reactor, nephron, material graph.

Golovanova O.A., Tomashevsky I.A.
Synthesis of nanocrystal calcium carbonate from bile in the presence of amino acids – page 962
Abstract: In this paper, we studied the effect of amino acids in the composition of bile, the formation of various modifications of calcium carbonate (aragonite, vaterite, calcite). In this work, 22 samples of calcium carbonate in bile were synthesized by varying the concentrations of amino acids (histidine, methionine, arginine and tryptophan). For the amino acids methionine and arginine, their stabilizing effect with respect to metastable aragonite has been proven: with an increase in their concentration in bile, an increase in the mass fraction of aragonite in the composition of the solid phase occurs. Optical microscopy showed the presence of vaterite spherulites in all obtained powders. The results of photon correlation spectroscopy correlate with the data of X-ray phase analysis. It is shown that calcium carbonate microparticles with a radius of less than 10 µm are represented by three fractions. It has been shown that syntheses involving histidine and tryptophan, in which, with increasing amino acid concentrations, an increase in the proportion of the small-sized fraction and a decrease in the proportion of the large-sized ones are observed. Thus, all studied amino acids have the potential to be used as medicines for the treatment and prevention of nanocholelithiasis.
Keywords: gallstones, crystallization, calcium carbonates, amino acids, additives, vaterite, radius, morphology.

Zaritovskii A.N., Kotenko E.N., Grishchuk S.V., Glazunova V.A., Volkova G.K.
Synthesis of carbon nanomaterials by means of microwave-assisted catalytic pyrolysis of cellulose – page 973
Abstract: The growing demand for carbon nanotubes, which are typical representatives of the class of carbon nanomaterials and have unique physical and chemical properties, necessitates the search for available and renewable hydrocarbon resources for their production and development of an energyefficient and a highly productive synthesis method. The prospects of using lignocellulosic biomass and its wastes as a carbon source for the synthesis of carbon nanotubes by means of microwave catalytic pyrolysis are considered. The expediency of research in this direction is emphasized. It is noted that one of the parameters responsible for the process of pyrolytic synthesis of carbon nanotubes is the concentration of microwave radiation absorber, which determines pyrolysis temperature. The effect of changing the concentration of microwave absorber in reaction mixture on the catalytic synthesis of multi-walled carbon nanotubes during microwave pyrolysis of cellulose has been studied. It is shown that a change in the microwave acceptor content from 10 to 30% is accompanied by an increase in the concentration of multi-walled carbon nanotubes of disordered morphology in reaction mixture. A twostage pyrolysis-synthesis process is suggested. The results of transmission electron microscopy and Xray phase analysis of the obtained products are considered.
Keywords: plant raw materials, carbon nanotubes, cellulose, microwave absorbers, concentration, microwave processing, pyrolysis.

Krut’ko V.K., Maslova L.Yu., Musskaya O.N., Kulak A.I.
Formation of biomimetic apatite on calcium phosphate foam ceramics in standard and carbonate-free model solutions – page 982
Abstract: The biomimetic apatite was formed in the carbonate-free Simulated Body Fluid model solutions of standard composition on calcium phosphate foam ceramics, consisting of α/β-tricalcium phosphate and β-calcium pyrophosphate. The apatite phase composition was determined by the composition of Simulated Body Fluid solution used during soaking. The equilibrium shift in the model solution during the interaction of calcium phosphate foam ceramics with ions of the solution leads to the apatite precipitation in the aggregated particles form. The excess content of Hions in carbonatefree Simulated Body Fluid leads to pH sharp fluctuations and the inclusion of hydrated СaClH2POimpurity into apatite spherulites. An increase in the soaking time in Simulated Body Fluid model solutions to 21-28 days leads to coarsening of apatite spherulites to 5-6 µm. The foam ceramics surface morphology after soaking changes insignificantly with a slight decrease in the through porosity by 1-3% and two times increase in static strength due to the healing of microdefects in the foam ceramics structure.
Keywords: calcium phosphate foam ceramics, tricalcium phosphate, SBF (Simulated Body Fluid), biomimetic apatite, spherulites.

Menshikov S.Yu., Malyshev A.N., Kurmacheva V.S., Tonkushina M.O., Ostroushko A.A.
The effect of FeSO4 and nanocluster polyoxometalates on the oxidation of phenol persulfate in an alcohol medium – page 992
Abstract: The catalytic properties of FeSO4, nanocluster ferro-molybdenum polyoxometalate {Mo72Fe30} and nanocluster molybdenum polyoxometalate {Mo132} have been studied during the oxidation of phenol in ethanolisobutanol solution with persulfate. To determine the oxidation products, phenol, ethanol and isobutanol of an acidic nature, sulfonic cation exchanger KU-2 (the grade of ion exchange resin established by the state standard of the Russian Federation GOST 20298-74) was added to the reaction mixture in each experiment to catalyze the esterification reaction of acid oxidation products with the initial alcohols. Acid esterification products were identified by the vapor-phase chromatography method with a mass spectroscopic detector. According to the conversion of phenol, ethanol and isobutanol, the catalytic properties of a homogeneous FeSO4 catalyst (similar to Fenton’s reagent) with heterogeneous catalysts (polyoxometalates) were compared. These data suggest the possibility of further searching for heterogeneous catalysts containing Fe and Mo in their composition during the destruction of phenol by peroxide compounds.
Keywords: polyoxometalate, Keplerate, FeSO4, catalytic properties, phenol oxidation in ethanol-isobutanol medium, potassium persulfate, gas chromatography mass spectrometry.

Musskaya O.N., Krut’ko V.K., Glazov I.E., Kulak A.I.
Liquid-phase synthesis of calcium phosphates in the presence of gallic acid – page 1000
Abstract: Acid, medium, and basic calcium phosphates were obtained by liquid-phase synthesis from aqueous solutions of calcium chloride and ammonium hydrogen phosphate at Ca/P molar ratios of 1,0-1,67 and pH 5-11 in the presence of a polyphenol compound (gallic acid). Using X-ray phase analysis and IR spectroscopy, it has been shown that brushite is formed in a slightly acidic medium (pH 5-6) at a Ca/P molar ratio of 1,0, the unit cell size of which can decrease in the presence of gallic acid. In an alkaline environment (pH 8-11), the polyphenolic compound chelates calcium ions, which leads to the formation of amorphized calcium phosphate, which after heating at 800°C turns into β-tricalcium phosphate and hydroxyapatite. It was found that the presence of gallic acid promotes the formation of basic calcium phosphate at a lower molar ratio (Ca/P 1,5) than for stoichiometric hydroxyapatite (Ca/P 1,67). It has been shown by thermal analysis that the liquid-phase synthesis of calcium phosphates in the presence of gallic acid promotes the transformation of brushite into calcium pyrophosphate, and amorphized calcium phosphates into tricalcium phosphate and hydroxyapatite, upon high-temperature treatment.
Keywords: gallic acid, liquid-phase synthesis, brushite, amorphized calcium phosphates, hydroxyapatite, tricalcium phosphate, calcium pyrophosphate.

Nalimova S.S., Shomakhov Z.V., Chuprova A.D., Guketlov A.M.
Synthesis and diagnostics of gas-sensitive nanostructures based on molybdenum compounds – page 1009
Abstract: In recent years, various transition metal dichalcogenides have been widely investigated, which are of interest for many applications, including gas sensors. In this work, some gas-sensitive nanostructures based on molybdenum disulfide and molybdenum oxide were synthesized by hydrothermal method. The surface chemical composition of the samples was studied by X-ray photoelectron spectroscopy. The gas-sensitive properties of the synthesized structures to isopropyl alcohol and acetone vapors at different working temperatures were analyzed. It was shown that as a result of heat treatment at 150°C, partial oxidation of molybdenum disulfide occured. Annealing of MoS2 samples at 400°C led to complete oxidation to MoO3. Analysis of the gas-sensitive properties of the structures showed that molybdenum oxide has the maximum response to isopropyl alcohol and acetone vapors in the entire temperature range under study. Both molybdenum disulfide and molybdenum oxide show a better response to isopropyl alcohol vapors compared to acetone vapors.
Keywords: chemisorption gas sensors, molybdenum disulfide, molybdenum oxide, X-ray photoelectron spectroscopy.

Ostroushko A.A., Tonkushina M.O., Zhulanova T.Yu., Kudyukov E.V., Golub A.Ya., Russkikh O.V.
Peculiarities of texture formation in strontium hexaferrite-based materials when produced from organic nitrate precursors – page 1017
Abstract: The processes of strontium hexaferrite (permanent magnet material) fabrication in combustion reactions followed by heat treatment of organic nitrate precursors containing glycine or polyvinyl alcohol have been studied. The formation of iron-glycine complexes of organic precursor components affects the formation of the morphology of the obtained samples. When using glycinecontaining systems during combustion, a branched fibrous texture of the material with extended internal cavities with elongated oxide particles emerges. Such samples have a higher coercivity; the external magnetic field has no significant influence on the texture formation during combustion. It was established that charges are generated in precursors during their combustion, which manifests itself in the appearance of a potential difference between the ground and the precursor. In this case, the appearance of lower intensity charges allows us to obtain samples with higher magnetization, as well as with a greater ability to increase the magnetic characteristics during further thermomagnetic processing.
Keywords: strontium hexaferrite, synthesis, organic nitrate precursors, magnetic properties, texturing.

Sviridova T.V., Yakubovskaya Z.A., Odzhaev V.B., Sviridov D.V.
Mechanism behind structural changes accompaning the solid-state polymerization in the molybdenumvanadium mixed oxide films – page 1029
Abstract: In this paper we investigate the changes in the surface topology of inorganic polymerderived films resulted from photostimulated polymerization. With the use of the atomic-force microscopy, the surface structure changes of mixed molybdenum-vanadium oxide thin films (V2O5:MoO3 = 3:2) resulted from the UV light-induced polymerization was investigated. The analysis of atomic-force images evidenced that the solid-state polymerization in the mixed oxide films obtained by condensation of corresponding oxoacids occurs through 3D mechanism. As the result of exposure, MoO3/V2O5 films lose the intrinsic anisotropy which is due to the directional agglomeration of belt-like mixed oxide oligomers. The photopolymerization processes in the mixed oxide film yield agglomerates of nuclei built from the faceted nanometer-sized pseudocrystallites. The exposure is also accompanied with solid-state recrystallization of initially amorphous oxide resulting in the rougher relief of the exposed film. The selective acidic etching uncovers the latent structure of the film, this etching being accompanied with pseudocrystallite dispergation that results in the smoothing of the microrelief of the oxide film surface. These structural features of photosensitive mixed oxide MoO3/V2O5 films facilitate their application as the inorganic photoresists.
Keywords: photopolymerization, molybdenum-vanadium mixed oxides, thin films, nanostructure, inorganic photoresists, atomic force microscopy.

Suprunchuk V.E.
Evaluation of the properties of the fucoidan/Fe3O4 nanocomposite as a transport agent of covalently bound molecular cargo – page 1039
Abstract: Magnetically controlled transport of drugs with targeted release of molecular cargo expands the possibilities of clinical therapy. This article explores the possibility of creating nanoparticles based on fucoidan modified with magnetite for biomedical purposes. The possibility of immobilizing a modelling fibrinolytic enzyme with a cross-linking agent was studied. The maximum loading of the enzyme is 2.06±0.09% of the mass. The particle size with immobilized alteplase according to scanningelectron microscopy was 94.4±24.3 nm, hydrodynamic diameter – 370 nm, zeta potential – -1.66±0.06 mV. The saturation magnetization of the sample is 6 emu/g. To understand the mechanisms of molecular load release, five kinetic models were applied to the results obtained: zero order, Weibull, Hill equation, Higuchi, Korsmeyer-Peppas. The use of mathematical modeling showed that the best model for describing this process is the Korsmeyer-Peppas kinetic equation (r2 = 0.97), and the release process is controlled by the Fick diffusion. The resulting biocomposite material is a promising candidate as a nanocarrier for an enzymatic agent.
Keywords: fucoidan, magnetite, magnetic nanoparticles, targeting, targeted delivery, alteplase, release kinetics, variable magnetic field.

Turovtsev V.V., Chernova E.M., Miroshnichenko E.A., Orlov Yu.D.
Effect of free valence on the electronic structure of n-alcohol radicals – page 1049
Abstract: The paper presents the results of a study of the effect of free valence (when a hydrogen atom is separated) on the electronic structure of n-alcohol radicals by the example of radicals of nheptanol derivatives (C●H2(CH2)6OH, CH3C●H-(CH2)5OH, C2H5C●H-(CH2)4OH, C3H7C●H-(CH2)3OH, C4H9C●H-(CH2)2OH, C5H11C●H-CH2OH, C6H13C●H-OH, C7H15-O●). Geometry optimization and the electron density distribution in these compounds was obtained by the density functional method B3LYP/6-311++G(3df,3pd) 6d 10f. The electronic structure of the selected molecules and radicals was investigated within the framework of the «quantum theory of atoms in a molecule» (QTAIM): the electronic parameters of atoms and atomic groups were calculated, the spin density distribution was studied, the concepts of «radical center» and «free valence» were quantitatively characterized. The inductive effect and the tolerability of atomic groups are considered, and a qualitative scale of group electronegatives is compiled. The disturbing effect of various atomic groups, including those containing free valence, on the hydrocarbon chain is compared by comparing the integral parameters of the groups included in the compounds under study with the parameters of the «standard» groups.
Keywords: quantum theory of atoms in molecules, electron density, electronegativity, inductive effect, free valence, radical center.

Khizhnyak S.D., Ivanova A.I., Volkova V.M., Barabanova E.V., Pakhomov P.M.
Green synthesis of silver nanoparticles. Complementary techniques for characterization – page 1059
Abstract: The work presents the results of green synthesis (biosynthesis) of silver nanoparticles using aqueous extracts of maple and oak leaves. The efficiency of the synthesis, size and shape of the formed nanoparticles were studied using UV-visible spectroscopy, dynamic light scattering, atomic force microscopy and scanning electron microscopy techniques. It was found that the formation of silver nanoparticles is accompanied by the appearance of a plasmon resonance band in the electronic spectra of aqueous extracts, the maximum of which depends on the concentration of silver nitrate and is in the range of ~420-429 nm in the spectra of maple leaves, and in the spectra of oak extracts there is a shift towards longer wavelengths ~425-435 nm, which correspond to the formation of nanoparticles of larger size. According to the dynamic light scattering data, the size of nanoparticles in the maple extracts is of about 60-68 nm and in the oak samples of ~107 nm. The differences in the size and shape of nanoparticles obtained in the maple and oak phytoextracts detected by atomic force microscopy and scanning electron microscopy are explained by the different composition of bioactive substances in the plants involved in the reduction of silver ions and stabilization or modification of the surface of silver nanoparticles.
Keywords: green synthesis, silver nanoparticles, surface plasmon resonance, scanning electron microscopy.

Cherkesova N.V., Mustafaev G.A., Mustafaev A.G.
Gate dielectric nitrization and effect on changes in the density of interlayer states of MOS structures – page 1070
Abstract: The processes occurring in the silicon-oxygen-nitrogen system are of great practical importance, since dielectric layers made from materials of this system are widely used as barriers to the penetration of impurities, elements of storage capacitors, field insulating layers, etc. Interest in the creation of such dielectrics has increased in connection with the use of the rapid thermal annealing stage in technological processes, which are accompanied by the appearance of fast surface states and mechanical stresses on the interface. As a result of the study, it was determined that the change in the threshold voltage in MDS structures is associated with the capture of electrons by the traps formed in the bulk of the semiconductor. MDS structures with nitrided oxide have better stability than conventional oxide. Studies have shown that the suppression of the formation of states at the interface depends on the degree of nitriding. The characteristics of MDS structures under the influence of irradiation substantially depend on the temperature and duration of fast thermal nitrization.
Keywords: metal–dielectric–semiconductor, silicon oxynitride, nitrization, gate dielectric, silicon dioxide, heat treatment.

Shkrumeliak V.A., Golovanova O.A.
Synthesis and study of the structure of lanthanum (III) compounds and cerium (III) with aspartic acid – page 1080
Abstract: A significant part of modern research is devoted to synthesis and study of the structure of compounds of rare earth elements with bioligands – these are those ligands that participate in biochemical processes. Compounds of rare earth elements with amino acids are of particular interest to study, since they are the most important bioligands, natural nanoscale molecules. In the course of the work, compounds of lanthanum (III) and cerium (III) with aspartic acid were synthesized. White crystalline precipitates were obtained for the «La-Asp» (1:2) and «Ce-Asp» (1:3) systems. With the help of optical microscopy, the fundamental difference between the crystals of synthesized compounds (in shape and size) from the crystals of the starting substances used for synthesis is proved. The results of IR-Fourier spectroscopy showed that metal ions interact with the carboxyl group of aspartic acid. The results obtained during the spectrophotometric analysis of the filler fluid for the «La-Asp» system (1:2) made it possible to simulate the spatial structure of this compound taking into account the amount of aspartic acid bound to lanthanum (III) ions. The synthesized compounds are promising for their further use in medicine.
Keywords: rare earth elements, complex compounds of lanthanum (III) and cerium (III), amino acids, aspartic acid, ligands.

ФХ-2022 Обложка (первый лист)

Foreword – page 7

1. EXPERIMENTAL STUDIES OF NANOPARTICLES, NANOSYSTEMS, AND NANOMATERIALS – page 8

Anufriev I.E., Muratova E.N., Korolev D.V., Shulmeister G.A., Valeev R.G., Moshnikov V.A.
Development of a manual extruder for liposome homogenization – page 8
Abstract: Medications using liposomes are of great interest in pharmaceuticals. They increase the therapeutic index of the drug by enclosing the medicinal substance inside a biocompatible lipid envelope, which releases the solution only in the required area. Such drugs have already shown their effectiveness in the treatment of diseases related to oncology, dermatology, neurology, surgery, etc. To use liposomes for these purposes, it is necessary that their size be in the range from 50 to 200 nm. There are several ways to create vesicles of this size, but mostly they use either ultrasound exposure to a liposome solution or extrusion. The extrusion method is a method that allows to obtain the most homogeneous solution from liposomal particles. For extrusion, a special device – an extruder is required. It is a system that passes a liposomal solution under pressure through a filter with a certain pore size. In this paper, the process of liposome extrusion, types of liposomal extruders are considered and their pros and cons are evaluated, a model of a manual extruder capable of homogenizing up to 20 ml of solution was also developed. Different materials were considered and used for the construction of this device. The inspection of the extruder showed its operability and showed the advantages of using extrusion compared to the ultrasound exposure method.
Keywords: extrusion, liposomes, homogenization, membrane, porous aluminum oxide, extruder, 3D modeling.

Apekov A.M., Shebzukhova I.G.
Orientational dependence of the interphase energy of low-temperature modification of titanium at the boundary with an organic liquid – page 17
Abstract: Calculations of the interphase energy of low-temperature modification of titanium at the boundary with nonpolar organic liquids are carried out within the framework of the electron-statistical method, corrections to the interphase energy for the dispersion interaction of Wigner-Seitz cells and the electron density oscillation in the transition layer, the polarization of surface metal ions and organic liquid in the field of a semi-infinite metal are obtained. When calculating the interphase energy, changes in all components of the metal bond energy in the transition layer are considered – the eigenenergies of the electron gas, the energies of the interaction of the electron gas with ions. The effect of an organic liquid on the orientational dependence of the interphase energy of alpha-titanium and the corrections to the interphase energy taking into account the permittivity of the organic liquid is established. It is shown that the dispersion and oscillation corrections increase the interphase energy, and the polarization correction reduces the interphase energy. A sharp anisotropy of the interphase energy and corrections is obtained for this titanium structure.
Keywords: interfacial energy, polarization correction, dispersion correction, electron-statistical method, non-polar organic liquid, titanium.

Barbin N.M., Yakupova L.V., Terent’ev D.I., Kuanyshev V.T.
Decomposition of fullerene C28 in a nitrogen atmosphere – page 24
Abstract: A study of the behavior of С28 fullerene when heated in a nitrogen atmosphere was conducted. The calculations were made using the thermodynamic modeling method, which consists in a complete thermodynamic analysis of the system using the TERRA software complex. The range of minimum and maximum heating temperatures was 273-3373 K and pressure was 0,1 MPa. A graph of the carbon balance in the С28 – N2 system was built, chemical reactions were determined, temperature intervals were allocated for each reaction. Temperature intervals of the thermal stability of carbon nanoparticles in the condensed and vapor phases are established. In the gas phase, С28 steam shows increased thermodynamic stability and only reacts with vapors at high temperatures, as evidenced by a sharp decrease in its content. The equilibrium constants of the reactions are calculated, and graphs of the dependence of the equilibrium constants of the reactions on temperature are given. For each reaction, the calculated data were approximated by the linear dependence.
Keywords: fullerenes, carbon nanoparticles, thermodynamic modeling, physical and chemical process.

Bernatskii D.P., Pavlov V.G.
The effect of the interaction of barium atoms on the surface of the rhenium field emitter on the work function – page 31
Abstract: Modification of the emission surface on a nanometer scale during adsorption of barium atoms on the surface of a rhenium field emitter was investigated using field electron and desorption microscopy. Field electronic images of the emitter surface reflecting the localization of barium atoms on the emitter surface, representing the quasi-spherical surface of a rhenium single crystal, were obtained. The influence of the temperature of the emitter with adsorbed barium on the change in the emitter work function is shown. Deposition at room temperature leads to the appearance of a dependence of the work function on the concentration of adsorbate with a minimum in the area of optimal coating. Annealing of the emitter at T = 600 K after deposition of each portion of barium causes the minimum to disappear. After reaching the minimum value (optimal coverage with adsorbed atoms), the work function remains constant with an increase in the number of adsorbed barium atoms on the surface of the emitter. A sharp change in the localization of barium atoms due to a phase transition with the formation of islands in the region of the rhenium face was detected on the field electronic image. The change in the nature of the dependence of the work function is associated with a phase transition in the barium film with the formation of barium islands. The concentration of barium in the islet is constant and corresponds to the optimal coating.
Keywords: field emitters, field electron and desorption microscope, adsorption, rhenium, barium.

Blinov A.V., Shevchenko I.M., Pirogov M.A., Gvozdenko A.A., Golik A.B., Leontev P.S.
Investigation of the effect of the molar ratio of reagents on the dimensional and structural characteristics of cobalt hexacyanoferrate nanoparticles – page 39
Abstract: In this work the influence of the molar ratio on the dimensional and structural characteristics of cobalt hexacyanoferrate nanoparticles was studied. The synthesis was carried out by chemical method in an aqueous medium using potassium hexacyanoferrate and cobalt nitrate. As a result of the study of samples by the method of dynamic light scattering, the values of the hydrodynamic radius of the samples were obtained. It was found that the minimum size (R = 76 nm) has a sample with a molar ratio K3[Fe(CN)6] : Co(NO3)2= 4 : 1. Scanning electron microscopy revealed that cobalt hexacyanoferrate samples are irregularly shaped aggregates consisting of nanoparticles with a diameter of 50 to 150 nm. As a result of X-ray phase analysis, it was found that the samples have a face-centered cubic crystal structure (Fm 3 m). According to the Debye-Scherrer equation, the average size of crystallites in the samples is from 17 to 20 nm.
Keywords: transition metal hexacyanoferrates, cobalt hexacyanoferrate, cobalt nitrate, scanning electron microscopy, dynamic light scattering, powder diffractometry, hydrodynamic radius.

Bolshakova N.N., Druginina N.Yu., Ivanova A.I., Pavlova D.N., Ped`ko B.B., Semenova E.M.
Repolarization properties of copper-containing crystals of triglycine sulfate – page 50
Abstract: The paper presents the results of the analysis of experimental dielectric hysteresis loops and field dependens of polarization switching of initial and annealed crystals of triglycine sulfate, doped copper (the concentration range (4,2–8,7) 10-3 wt.%). It has been experimentally established that their dielectric hysteresis loops do not have distortions. It has been found that the relative and effective permittivities and switchable polarization increase with increasing impurity concentration in crystals of TGS:Cu2+. The field dependences of the effective permittivity have extrema: before annealing the samples, the maxima of the εeff(E) curves correspond to a field value of about (20-40)∙103 V∙m-1, and for annealed samples these fields have a value of ~(15-30)∙103V∙m1. Annealing of the samples increases the mobility of domain walls, which promotes the transformation of lenticular nuclei of domains into lamellae.
Keywords: triglycine sulfate, repolarization, domain structure, switching processes, hysteresis, permittivity.

Golovanova O.A.
Study of calcium oxalate nanocrystalline structures and kinetics of calcium oxalate deposition – page 61
Abstract: Calcium oxalates, represented by wavellite CaC2O4·H2O and weddellite CaC2O4·2H2O (the most stable forms), are the main components of stones in the genitourinary system, and are also part of dental, gallstones, and other mineral deposits. It is known that modern approaches to the study and modeling of crystallization processes make it possible to analyze the influence of a number of factors (exogenous and endogenous) arising at various levels of organization: from atoms and molecules to macroscopic processes occurring in industrial devices. The process of crystallization, taking into account the variety of acting factors and forms of crystal structures, consists of two main stages: formation of a solid phase nucleus and its growth (formation of a solute crystal). In this work, using modern approaches, the physicochemical and kinetic patterns of crystallization of calcium oxalates under conditions close to physiological are determined. The effect of physiological solution components (organic and inorganic) was studied, the staged mechanism of the solid phase formation was established, and the kinetic parameters of the growth stage were calculated (lgk = 33.1). The inhibitory effect of inorganic additives (Mg2+, Cl), amino acids (glycine, glutamine, aspartic) and the accelerating effect of hydroxyapatite crystals, seed in the form of calcium oxalate and urea crystals on the crystallization process were revealed.
Keywords: .

Golovanova O.A.
Crystallization of nanocrystalline hydroxylapatite in the presence of albumin – page 71
Abstract: Due to the development of modern biotechnologies and nanomaterials, in the near future it is expected to achieve a new, higher quality level in the design and improvement of the characteristics of intraosseous implants used in orthopedics. Calcium phosphate was synthesized from a model solution of synovia in the presence of albumin. Synthetic solid phases were studied using X-ray phase analysis, IR-Fourier spectroscopy, scanning electron microscopy, and energy dispersive analysis. The supernatant was examined for the presence of ions and to calculate the ratio. It was found that albumin does not affect the phase composition of the samples: the sediments are single-phase and consist of B-type hydroxylapatite carbonate. The study of the structure and morphology of the solid phase showed that the presence of proteins leads to formation of composites with a lower specific surface area compared to hydroxylapatite carbonate. The largest crystallite size is observed for the hydroxylapatite carbonate /albumin sample with the albumin concentration of 12 g/l. With the help of the thermal analysis of the fixation of thermal effects five stages of the thermal transformation were identified in the temperature range of 25-1000 °C; for all samples, the main stages are II–III, associated with the thermal destruction of organic additives. The study of the bioactivity of the samples showed that in the case of active resorption, the most soluble were the samples synthesized in the presence of albumin (>7 g/l), and in the case of passive resorption, the hydroxylapatite carbonate/albumin samples (5 and 7 g/l).
Keywords: crystallization, hydroxylapatite, albumin, adsorption, bioresorbability.

Gudkov S.I., Solnyshkin A.V., Zhukov R.N., Kiselev D.A.
Electrical response of lithium niobate and lithium tantalate thin films to modulated thermal radiation – page 82
Abstract: In this work, we studied the pyroelectric activity of thin polycrystalline lithium niobate films fabricated by radio frequency magnetron sputtering and laser ablation, and thin polycrystalline lithium tantalate films fabricated by radio frequency magnetron sputtering. Using the dynamic method of studying the pyroelectric effect, it was found that all samples have self-polarization that occurs during the post-growth thermal annealing of the structure. An estimate of the pyroelectric coefficient showed that the values of the pyroelectric coefficient of lithium niobate and lithium tantalate thin films are several times lower than the values of the pyroelectric coefficient for bulk crystals of the corresponding materials. This may be due to the fact that the polarization vector of some grains lies in the film plane, as well as to the traps existing in the film volume and at the film/substrate interface, on which charge carriers recombine and do not participate in the generation of the pyroelectric current.
Keywords: lithium niobate, lithium tantalate, thin film, dynamic method, self-polarization, pyroelectric effect, pyroelectric coefficient, LiNbO3, LiTaO3, ferroelectric, laser ablation method, radio frequency magnetron sputtering.

Zernitsa D.A.
Crystallization of lead-free binary tin-zinc alloys produced by the method of rapidly solidification from the melt – page 92
Abstract: The results of studies of the structures of rapidly solidified foils of alloys of the Sn – Zn system with a low content of alloying elements (up to ~1,5 wt.%), alloys of near-eutectic compositions, as well as alloys with an alloying element content of 20 – 95 wt.% are presented. In rapidly solidified alloys containing 1,5 wt. % Sn and 1,2 wt. % Zn, supersaturated solid solutions are formed, which decompose according to the mechanism of formation and growth of nuclei of a new phase at room temperature. Alloys (4,4 – 15 wt.% Zn) after rapidly solidification are supercooled and supersaturated with both components, and experience spinodal decomposition followed by the formation of supersaturated solid solutions based on Sn and Zn, which decompose at room temperature. In all other alloys, a two-phase structure is formed from solid solutions based on Sn and Zn. It was found that as the crystallization front moves from the surface of the contacting foil layer with the surface of the mold, the Sn particles coarsen and the specific surface of the interface
decreases. It has been established that rapidly solidified foils have a microcrystalline grain structure, with an increase in the concentration of alloying elements, a tendency to a decrease in grain size is observed.
Keywords: rapidly solidified alloys, zinc, tin, grain, spinodal decomposition, supersaturated solution, eutectic, structure.

Zigert A.D., Semenova E.M., Kuz`min N.B., Sdobnyakov N.Yu.
Fractal analysis of magneto-optical images of a magnet surface after exposure to a pulsed field – page 101
Abstract: The results of fractal analysis of images of the surface of a permanent magnet KS37 obtained by the method of the polar Kerr effect using an indicator bismuth-containing ferrite-garnet film after magnetization reversal by a pulsed field of 0,1 – 1,5 T are presented. The obtained dependences of the remanent magnetization on the magnitude of the external pulsed field are compared with the fractal dimension of the magneto-optical images of the magnet surface after exposure to the pulsed field. It is hypothesized that the field dependences of the fractal dimension of the profile of magneto-optical images of the magnet surface coincide in shape with the graphs of the first derivative dMr(H)/dH of the magnetization with respect to the field, i.e. there is a relationship between the nature of the magnetization change in a pulsed field and the type of the magneto-optical image analyzed by using the fractal geometry methods.
Keywords: permanent magnet, effect, ferrite-garnet films, domain structure, fractal dimension, derivative of magnetization with respect to magnetic field.

Ivanov D.V., Antonov A.S., Semenova E.M., Ivanova A.I., Kuz`min N.B., Sdobnyakov N.Yu.
On the formation of fractal iron films – page 108
Abstract: The patterns of formation of the fractal relief of nanosized iron films on the mica surface are considered using the atomic force microscopy. In order to prevent the formation of an oxide layer, iron films were studied immediately after their production employing at a magnetron sputtering unit. It has been established that magnetron sputtering makes it possible to obtain island films of iron, the structural element of which are truncated nanocubes – nanopyramids. The fractal dimension of the resulting agglomerates was determined at various scales: on a scale of 5 µm Dc = 2,462±0,113; on a scale of 3 µm Dc = 2,373±0,122; on a scale of 1 µm Dc = 2,298±0,139. The distribution of the probability of detecting agglomerates on the films under study with a certain fractal dimension of the surface of iron films is estimated. The subsequent elemental analysis of the iron films showed the presence of oxygen and, consequently, the formation of ordered oxide films of the core-shell type.
Keywords: atomic force microscopy, magnetron sputtering, fractal dimension, iron films, nanopyramids.

Ivanova A.I., Svesnikov P.A., Marinicheva K.A., Gugutsidze K.A., Vasilev A.D., Tretiakov S.A., Karpenkov A.Yu.
Comparative studies of the strength properties of germanum and silicon single crystals – page 120
Abstract: In this paper, we present the results of microhardness tests performed by Vickers indentation of germanium and silicon single crystals. It’s shown that in the investigated samples there is a dependence of microhardness on the crystallographic directions and the nature of the alloying impurity. Microhardness anisotropy coefficients are calculated: for germanium KII=1,2 and for silicon KII=1,3. The analysis of high-temperature annealing influence on microhardness value of germanium and silicon crystals is carried out. It has been established, that the microhardness of Ge(111) crystals grows on 12% after annealing at 550°С, the further thermal processing of germanium crystals at T=650°С considerably changes the structure and surface relief which contribute to a decrease in microhardness values. It is shown that the microhardness of silicon crystals increases by 10% after annealing at 750°C, further annealing to T=850°C leads to a decrease in microhardness. The surfaces of single crystals after high-temperature annealing have been studied; it has been established that thermal treatment at T≈0.6 Tm (Tm – the melting temperature of the single crystal) leads to the appearance of defects and a tenfold increase in the maximum height of the surface profile (from 10-12 nm to 100-200 nm).
Keywords: germanium and silicon single crystals, microhardness, Vickers method, microhardness anisotropy coefficient, interatomic bonds, dopants, high-temperature annealing, surface nanorelief, defects.

Ivanova A.I., Musabirov I.I., Semenova E.M., Vasilev A.D., Gugutsidze K.A., Karpenkov A.Yu.
Influence of deformation on the microsructure and magneic properties of Heusler alloys – page 132
Abstract: This paper presents the results of studies of the effects of deformation obtained by the method of multiple isothermal forging on the microstructure and magnetic properties of the NiMnGa alloy system. It is shown that the microstructure of the initial alloy during deformation undergoes changes, grain size decreases and a two-component structure is formed. The magnetic domain structure of the original and deformed alloys was visualized by magnetic force microscopy. It is shown that the distortion of the domain shape is associated with the presence of a martensitic relief and grain boundaries, 180-degree magnetic domains are continuous within the crystallites, while they cross the flat parallel boundaries of the martensite plates. The study of temperature and field magnetization dependences of the initial and isothermal forging samples demonstrates an insignificant magnetization decrease and a shift of the phase transition temperature toward low temperatures. It’s concluded that deformation by the isothermal forging method can be considered as a way to correct the phase transition temperature in NiMnGa alloys with preservation of magnetization.
Keywords: Heusler alloys, martensitic relief, multiple isothermal forging, micro and nanostructure, magnetic domain structure, magnetostructural transition.

Karmokova R.Yu., Karmokov A.M., Molokanov O.A., Khasanov A.I., Kanametov A.A.
Influence of the parameters of acoustic waves on the characteristics of cavitation bubbles in liquid aluminum – page 141
Abstract: Calculation of parameters of a cavitation bubble during irradiation of aluminum melt with acoustic waves is carried out. The dependences of the Mach number on the amplitude at frequencies of 1-20 kHz used in the experiments are obtained. A relationship has been established between the resonant frequency of acoustic waves and the size of cavitation bubbles in liquid aluminum. Allowing the possibility of generalizing the Minnert linear theory to the case of viscous liquids, the dependence of the maximum radius of cavitation bubbles on the frequency of the acoustic field at different temperatures is obtained, taking into account the surface tension, density and viscosity of liquid aluminum. It has been established that with an increase in the frequency of the acoustic field, the radii of the cavitation bubbles decrease. The temperature change inside the cavitation bubble is estimated as a function of the bubble radius at any moment of its compression under adiabatic conditions. It is shown that when the bubble radius decreases to a critical size, the temperature inside it can increase by an order of magnitude.
Keywords: aluminum, acoustic waves, cavitation, cavitation bubble, Mach number.

Karpenkov A.Yu., Rakunov P.A., Musabirov I.I., Dunaeva G.G.
Influence of deformation processing on magnetocaloric effect of Heusler alloys – page 149
Abstract: This paper presents the results of complex studies of the effect of deformation obtained by the multiple isothermal forging method on the magnetocaloric properties of the Ni-Mn-Ga Heusler alloy system. Direct measurements of the adiabatic temperature change show that cycling the sample in a magnetic field μ0ΔH=1,85 T can decrease the maximum of ΔTad(T)0→H by the value corresponding to the latent heat of transition. Neglecting this transformation effect leads to an overestimation of the magnetocaloric effect of materials with the first-order transition. An analysis of the deformation treatment effect on the phase transformation temperatures and the magnitude of the magnetocaloric effect indicates that the application of multiple isothermal forging leads to a small decrease of the magnetization and the magnitude of the magnetocaloric effect. Deformation also causes a shift in the phase transition temperature towards low temperatures and decrease of the temperature hysteresis width.
Keywords: Heusler alloys, multiple isothermal forging, magnetocaloric effect, magnetostructural phase transition.

Kul’kov V.G., Kul’kova V.V.
Internal friction caused by migration of the intercrystalline boundary in the metal – page 159
Abstract: The model of internal friction at the migrating intercrystalline boundary is considered. Under the action of an alternating external stress oriented normally to the boundary, compression and stretching of the mating crystallites occurs. Due to their anisotropy and mutual reversal, Young’s modules in the direction of the stress action are different. The volume density of elastic energy in crystallites is different. This leads to the emergence of an effective driving force for boundary migration. As a model, a square segment of the boundary is selected, fixed along the perimeter by triple grain joints. The Laplace stress from the side of the curved boundary is counteracting. The differential equation of the connection of the boundary displacement with the total voltage is solved by the Fourier method. Based on this solution, the internal friction is calculated. The relaxation time spectrum consists of a series of lines. Each of them corresponds to the peak of Debye. The main peak has a significant value, smaller peaks are superimposed on it. The resulting maximum of internal friction widens in comparison with the Debye peak.
Keywords: driving force, migration of the intercrystalline boundary, peak of internal friction, relaxation time.

Lapin V.A., Kasyanov I.V.
The growth of InAlN/Si heterostructures with a high content of In – page 168
Abstract: InAlN films on Si (111) were obtained by the ion-beam deposition with various technological growth parameters. The results of the study of grown films by the scanning electron microscopy were used to identify the conditions for obtaining InAlN continuous films. Due to the mismatch of the lattice parameters of the film and substrate, the growth has an island character, a solid film was obtained only with the following technological parameters: the energy level of the beam U = 600 eV at the ion current of the beam ji = 32 mA, with the neutralization current of the beam jn = 32 mA, the substrate temperature of 400°C. With an increase of the nitrogen concentration to 80-90% in the gas mixture, a transition from an island to an epitaxial growth mechanism took place. The ratio of the elements In, Al and N in the film showed that the active plasma of the ion beam breaks down weakly bound ions and leaves only normally embedded nitrogen atoms N-3, but excessively strong exposure leads to metallization of the films.
Keywords: heteroepitaxy, InAlN, ion-beam deposition, elemental analysis, scanning electron microscopy, heterostructures.

Malashenko V.V., Malashenko T.I.
Effect of dislocation density on the dynamic yield strength of alloys with nanoscale defects under high energy external actions – page 176
Abstract: A theoretical analysis of inelastic processes in aged alloys under intense external influences is carried out. The analysis was carried out within the framework of the theory of dynamic interaction of defects. An analytical expression for the dependence of the dynamic yield strength on the dislocation density has been obtained. The reason for the different influence of nanostructural defects on the dislocation motion under high strain rate deformation and quasi-static deformation is determined. It is shown that under high strain rate deformation, nanosized defects affect the nature of the dependence of the dynamic yield strength on the dislocation density. This dependence becomes nonmonotonic and has a minimum. At the minimum point, there is a transition from the dominance of the drag of the dislocation by Guinier-Preston zones to the dominance of its drag by other dislocations. Numerical estimates of the contribution of the Guinier-Preston zones to the yield strength are made. It is shown that at a high concentration of Guinier-Preston zones, this contribution is very significant. Numerical estimates are made of the dislocation density at which the Taylor relation is violated.
Keywords: high-speed deformation, dislocations, Guinier-Preston zones, point defects, nanomaterials, Taylor ratio.

Malyshkina O.V., Ivanova A.I., Mamaev D.V.
The effect of tellurium vapor on the structure formation and dielectric properties of a multicomponent system based on sodium-potassium niobate – page 183
Abstract: The paper presents the results of studying the effect of paratellurite vapor during sintering on the dielectric properties of a multicomponent system based on sodium–potassium niobate ceramics (mKNN) with the general formula (Na0,5K0,49Li0,05Sr0,05)(Nb0,9Ta0,05Ti0,05)O3. The inclusion of paratellurite in mKNN ceramics changes the shape and increases the grain size by an order of magnitude. Thus, if grains containing only mKNN material have a cubic shape, then the presence of tellurium leads to the formation of grains in the form of sufficiently long tubes (when the length is several times greater than the diameter) with a porous internal structure. The addition of TeO2 to the mKNN composition leads to the disappearance of the maximum observed for mKNN on the temperature dependence of the permittivity in the region of 220-250°C, which corresponds to a nonferroelectric structural phase transition in KNN ceramics, and to smoothing the resonant- antiresonant peak in the range of 5-15 MHz, which appears in the KNN system with the introduction of modifiers.
Keywords: piezoelectric ceramics of potassium sodium niobate, lead-free materials, grain structure, complex permittivity dispersion.

Malyshkina O.V., Shishkov G.S., Ivanova A.I.
Structure and dielectric properties of a layered composite of barium titanate – barium ferrite – page 194
Abstract: The paper presents the results of a study of the influence of a constant magnetic field on the dispersion of the complex permittivity of a layered composite (connectivity 2-2) based on barium titanate – barium ferrite. It is shown that in the manufacture of a magnetoelectric composite of barium titanate – barium ferrite with a connectivity of 2-2, a strong diffusion of iron appears into the barium titanate ceramic layer at the interface between the two materials. It was found that iron penetrates evenly, with random deviations, and no exponential decline as iron enters into barium titanate is observed. It has been established that a constant magnetic field does not affect the dielectric characteristics in an alternating electric field at frequencies above 1600 Hz. At lower frequencies, annealing in the paraelectric phase increases the resistance of the sample, and subsequent exposure to a constant magnetic field leads to its decrease. It was revealed that changing the type of connectivity of the magnetoelectric composite from 0-3 to 2-2 adds additional, smaller, resonance and
antiresonance peaks in the study of piezoelectric properties by the resonance-antiresonance method. At the same time, the samples have sufficient values of the piezoelectric modulus for practical application (d31 > 40·10-12 C/N; d33 > 120·10-12 C/N).
Keywords: multiferroic, barium ferrite, barium titanate, magneto-electric composite, piezoelectric ceramic structure.

Maraeva E.V., Tokmeilova S., Sagitova D.R., Kononova I.E., Moshnikov V.A., Skornikova S.A.
Study on the microporous structure parameters of BEA type zeolites – page 203
Abstract: The paper considers a series of zeolite materials used as catalysts. Since the formation of mesoporosity in a microporous matrix is one of the methods for increasing the efficiency of zeolite materials in catalysis, it is necessary to control their porous structure parameters. The effect of post-synthetic treatment with acid and alkali solutions on the specific surface area of zeolites of the BEA type has been studied. The method of low-temperature (at 77 K) adsorption of nitrogen vapors was used to determine the external specific surface area (excluding micropores) and the volume of micropores in the samples on a Sorbi device. It has been shown that modification of BEA-type zeolite with concentrated mineral acids leads to both a decrease in the volume of micropores and a decrease in the specific surface area. At the same time, it was established by the X-ray phase analysis that the treatment with concentrated acids does not lead to destruction of the crystal structure of zeolites. In the case of treatment with alkali solutions, the specific surface area of the samples increases and the volume of micropores sharply decreases.
Keywords: zeolites, BEA type, hierarchy, mesopores, micropores, adsorption, specific surface area.

Nepsha N.I., Veselov A.D., Savina K.G., Bogdanov S.S., Kolosov A.Yu., Myasnichenko V.S., Sdobnyakov N.Yu.
Variability of structural transformations in bimetallic Cu-Ag nanoalloys – page 211
Abstract: In this work, bimetallic Cu-Ag nanoparticles of five stoichiometric compositions of various sizes were studied by molecular dynamics method using a many body EAM potential. Regularities of the structure formation are established, their characteristic features are described. In particular, in compositions with 10, 70, and 90 at.% Cu content, after the melt cooling, typical fcc structures with intersecting atomic planes of the hcp phase are formed. In compositions of 30 and 50 at.% Cu, the fraction of identified phases does not exceed 20% of the total number of atoms. A tendency to the formation of a core-shell structure was revealed in the case of a high copper content, while in the case of a high silver content, a so-called onion structure is formed. Using the caloric curves of the potential term of the internal energy, the melting and crystallization temperatures were determined. It has been established that the concentration dependences of the melting temperature of bimetallic Cu-Ag nanoparticles have a minimum corresponding to the equiatomic composition for all sizes. For the crystallization temperature, both the concentration dependences and the size dependences are less pronounced, but the minimum value of the crystallization temperature also corresponds to the equiatomic composition for all sizes; with an increase in the size of bimetallic Cu-Ag nanoparticles, a slight increase in the crystallization temperature is observed.
Keywords: molecular dynamics method, LAMMPS, EAM potential, polyhedral template matching method, bimetallic nanoparticles, silver, copper, structure formation, melting and crystallization temperatures.

Sidorov N.V., Smirnov M.V., Titov R.A., Teplyakova N.A., Palatnikov M.N.
Optical properties of LiNbO3:B crystals – page 227
Abstract: The optical properties of nominally pure LiNbO3stoich, near-stoichiometric LiNbO3stoich (6,0 wt% K2O), LiNbO3cong and LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals in the visible region of the spectrum (λ = 380-700 nm) were studied by photoluminescence. LiNbO3:B crystals were grown by Czochralski using the technology of a direct solid-phase doping of the congruent charge by boron oxide (B2O3). The photoluminescence intensity increases in the series of crystals: LiNbO3stoich, LiNbO3stoich (6,0 wt% K2O), and LiNbO3cong. The photoluminescence intensity is determined by the concentration of deep electron traps (NbLi – «niobium antisite») and the stoichiometry of these crystals. The photoluminescence intensity of LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals is close to the photoluminescence intensity of LiNbO3stoich crystal. This can be explained by the fact that the composition and structure of LiNbO3:B (0,55 and 0,83 mol% B2O3 in the charge) crystals approach the composition and structure of the stoichiometric crystal.
Keywords: lithium niobate, crystal, defects, direct solid-phase doping, photoluminescence.

Sidorov N.V., Kadetova A.V., Titov R.A., Teplyakova N.A., Palatnikov M.N.
Specific features of the defect structure of LiNbO3:B crystals – page 235
Abstract: Specific features of the defect structure of nominally pure LiNbO3:B crystals were studied by the X-ray diffraction analysis. Nominally pure LiNbO3:B crystals were grown by Czochralski using the technology of the direct solid-phase doping of the congruent charge by orthoboric acid (H3BO3). The bonds lengths of Me-O in MeO6 clusters (Me-Li, Nb) determine the ferroelectric and nonlinear optical properties of the lithium niobate crystal. The values of these bonds in LiNbO3:B crystals differ significantly from the bonds lengths of the nominally pure congruent crystal LiNbO3cong. The differences in the bonds lengths are caused by a change in the properties of the boron-containing melt, technological parameters of the growth of LiNbO3:B crystals, and the localization of a trace amounts of boron in tetrahedral voids of the lithium niobate crystal structure. The results of the study of LiNbO3:B crystals were compared with those for nominally pure LiNbO3cong crystals and near-stoichiometric LiNbO3stoich (5,5 wt% K2O) ones.
Keywords: lithium niobate, crystal, defects, direct solid-phase doping, X-ray diffraction analysis.

Strechen A.S., Kurnosov Yu..A., Karpenkov A.Yu.., Ivanova A.I., Sinkevich A.I., Semenova E.M., Pastushenkov Yu..G.
Surface study of Tb0,16Ho0,84Fe2,00-xCox intermetallics – page 243
Abstract: The results of the study of the crystal structure, magnetic properties, as well as of micro-and domain structure of the surface of a series of compounds Tb0,16Ho0,84Fe2,00-xCox (x = 0,1; 0,2; 0,3; 0,4) are presented. It is shown that an increase in the relative content of cobalt leads to a decrease in the crystal lattice parameter a from 7,310 Å at x = 0,1 to 7,304Å at x = 0,4. At the same time, the Curie temperature increases accordingly from 581 to 614 K. It has been experimentally established that, as x increases, the specific saturation magnetization decreases linearly with increasing temperature. It has been found that the mechanical impact on the surface of sections during polishing can lead to the appearance of a regular microrelief. The results of studying the domain structure of the surface are presented. It is shown that the configuration and linear dimensions of the domains change as a result of the impact on the surface of the samples.
Keywords: intermetallics, Laves phase, magnetic properties, surface, microstructure, domain structure.

Elcheparova S.A., Kokoevа A.A.
Luminescent method for determination of nanoscale particles of rare earth elements with sulfosalicylic acid derivatives – page 254
Abstract: It was of interest to search for luminescent reactions to terbium in complexes with sulfosalicylic acid derivatives and to enhance them by studying the effect of third components (aminopolycarboxylic acids, organic bases and surfactants). As the results of the conducted studies have shown, surfactants increase the intensity of the glow of terbium ions in complexes with sulfosalicylic acid derivatives. The existence of a bright luminescent reaction of green terbium in complex with the methyl ester of S-(4-bromanilide) sulfosalicylic acid has been established. Optimal conditions for the complexation of terbium have been selected and highly sensitive luminescent methods for the determination of terbium in various objects have been developed. Terbium is converted into a luminescent complex compound with an organic reagent –
methyl ether S-(4-bromanilide) sulfosalicylic acid in the presence of a cationic surfactant decylpyridinium chloride in a ratio of 1: 2: 13, pH = 7,9 ± 0,08. The resulting complex compound of terbium, when irradiated with ultraviolet light from a mercury lamp, gives intense green luminescence, stable during standing and irradiation. The proposed method makes it possible to determine terbium in oxides of rare earth elements, which are luminescence quenchers with a sensitivity of 10-6 – 10-8%, bypassing the extraction stage.
Keywords: nanoscale particles, rare earth elements, lanthanides, organic reagent, complex compound, terbium, luminescence, detection limit.

2. THE THEORY OF NANOSYSTEMS – page 264

Anofriev V.A., Nizenko A.V., Ivanov D.V., Antonov A.S., Sdobnyakov N.Yu..
To the problem of automation of the process of determination of the fractal dimension – page 264
Abstract: In this paper, using various software products (Gwyddion, Mountains 9 DigitalSurf, Image Analysis P9) as well as our own program FractalSurface, we analyzed the possibilities of calculating the fractal dimension for various types of data using several numerical methods (cube counting method, triangulation method, variation method, as well as methods of the spectrum power, «scaling» analysis, morphological envelopes) and the possibilities for their working with the obtained values, such as: selecting a linear section of the graph for recalculating the final value of dimension, using matrix convolutional filters with different convolution kernels for image processing and of the batch analysis of the studied images. At the current time, there is no software product that would satisfy all the requirements for image analysis for the presence of self-affine structures, however, the availability of sufficient functionality mainly depends on the type of study. The comparative analysis of the obtained results allows us to evaluate the capabilities of the software product for further use as tools for automating the process of determining the fractal dimension and of the primary image processing.
Keywords: fractal dimension, cube counting method, triangulation method, variance method, power spectrum method, scaling analysis method, morphological envelopes method, image processing software.

Akhmatov Z.A., Akhmatov Z.A.
On the possibility of controlling the band gap in graphene – page 277
Abstract: Using first principles calculations, the possibility of controlling the electronic band structure of the single-layer graphene was investigated. It is shown that when potassium atoms are adsorbed on the graphene surface, an energy gap appears in its electronic spectrum. It was also observed that the band gap strongly depends on the number of adsorbed atoms, namely, with an increase in the number of adsorbed atoms, the band gap in graphene can either increase or disappear. For example, when there is one potassium atom per 32 carbon atoms in the graphene lattice, the band gap is ΔE = 0,1 eV. An increase in the number of potassium atoms to two leads to disappearance of the energy gap, while for three potassium atoms ΔE = 0,22 eV. It should also be noted that the appearance of a band gap during adsorption does not break the symmetry of the graphene sublattices. This observation seems interesting to us, since according to many authors, it is the break of the sublattices symmetry that is the main reason for the appearance of a band gap in graphene.
Keywords: graphene, electronic band structure, ab initio calculations, adsorption, alkali metal atoms.

Belyaeva I.N., Kirichenko I.K., Chekanova N.N.
Solving of some nonlinear ordinary differential equations in the form of power series – page 284
Abstract: In the current scientific literature, a variety of nonlinear ordinary differential equations are widely and successfully used to describe real processes in various fields of natural sciences: optics, elasticity theory, molecular physics, etc. For example, the Ermakov and Riccati equations are used to solve the quantum Schrodinger equation, in electrodynamics. However, unfortunately, there are no well-and reliably developed and generally accepted methods for solving nonlinear differential equations. In addition, most of the Riccati equations are not integrated even in quadratures. In this paper, to construct solutions to the nonlinear Ermakov and Riccati equations, it is proposed to use the corresponding so-called connected linear differential equations, the solutions of the latter are in the form of power series using modern computer systems of analytical calculations.In this paper, solutions for some nonlinear Ermakov and Riccati equations are calculated using this proposed method. It is shown by direct substitution that the obtained solutions in the form of power series satisfy the considered nonlinear equations of Ermakov and Riccati with a known accuracy. Solutions of nonlinear Ermakov and Riccati equations can be used to describe the chemical and physical properties of nanostructures at the quantum level. Besides, solutions of nonlinear Ermakov and Riccati equations can be successfully applied in solving stationary and time-dependent Schrodinger equations.
Keywords: ordinary differential equations, Ermakov equation, Riccati equation, mathematical modeling, power series, Maple computer system.

Zamulin I.S., Gilubnichiy A.A., Chepkasov I.V., Baidyshev V.S.
Methods for describing the reactivity of transition metal nanoparticles – page 292
Abstract: Using modern calculations from first principles, in this work we systematically studied the adsorption of atomic oxygen on the surface of nanoparticles of fcc metals Ag, Cu, Pd consisting of 79 atoms. Two models were considered to describe the reactivity of transition metals based on the d-band center of surface atoms, as well as on the basis of the generalized coordination number. Both methods for predicting the adsorption energy of oxygen atoms at different sites have shown good results, however, the method based on the generalized coordination number is computationally simpler, since this method requires information only about the structure of the particle, while the d-band center model requires electronic structure calculations. The obtained values of the oxygen adsorption energy and d-band center correspond to the known literature data. The most favorable positions for the adsorption of an oxygen atom are on the (100) plane and are hollow consisting of 4 atoms and do not depend on the type of metal under consideration. The highest adsorption energy of the oxygen atom was observed in the case of copper nanoparticles.
Keywords: transition metals, nanoparticles, generalized coordination number, adsorption, electron density functional theory.

Magomedov R.A., Akhmedov E.N.
Water vapor P-ρ-T properties calculation in the temperature range from 773 K to 1673 K – page 298
Abstract: The paper presents the calculation of isotherms of the equation of state of water vapor in the temperature range from T = 773 K to T = 1673 K. The calculation was made using a specially developed software module “Fract EOS”. An approach that improves the accuracy of calculations of the previously described method is proposed. If there are tabular data of the P-V-T (P-ρ-T) ratio for several temperatures and the pressure dependences of the fractional derivative exponent α(ρ) (which is fitting parameter for the proposed model) obtained from them, then it is possible to obtain the dependence α(ρ) for any temperature within the range. After that, the equation of state can be calculated at a given temperature with high accuracy, without fitting α by experimental values. The results obtained are in good agreement with experimental data. It is shown that proposed method is suitable for calculating isotherms in the temperature ranges not presented in tabulated reference data.
Keywords: equation of state, integral-differentiation of fractional order, Maxwell relations, Helmholtz potential, partition function, water vapor, isotherm, thermophysical properties.

Talyzin I.V., Samsonov V.M., Bogdanov S.S., Sdobnyakov N.Yu.., Grigoryev R.E., Pervikov A.V., Mishakov I.V.
Identification of complex core-shell nanostructures from the radial distributions of the local density of components – page 307
Abstract: The paper is devoted to the substantiation and further development of the approach to the analysis of the mesoscopic and integral structure of binary metal nanoparticles from the radial distributions of the local density of the components. As an example, the local density distributions of Ni and Al obtained using the results of molecular dynamics modeling of binary Ni-Al nanoparticles with an initial uniform distribution of components and Ni@Al core-shell icosahedral nanostructures are considered. Both patterns demonstrate the surface segregation of Al atoms during relaxation and subsequent quenching of the initial configurations containing 5000 atoms in 1:1 ratio (nanoparticle radius 3 nm). During cooling, the temperature of the nanoparticles decreased from 1000 K to 0,01 K with a low for atomistic simulation cooling rate. Experimentally binary Ni-Al nanoparticles with a radius of about 100 nm (76Ni:24Al at.%) were synthesized by the wire electric explosion. The experimental intensity distributions obtained from the data of energy-dispersive analysis under the action of an electron beam are presented and analyzed. These distributions correspond to a greater extent to the initial configurations in our molecular dynamics experiments, i.e., they are obviously nonequilibrium. At the same time, it was concluded that the final molecular dynamic configurations are also not entirely equilibrium.
Keywords: core-shell nanostructures, Ni-Al nanoparticles, radial density distributions, embedded atom method, tight binding potential, molecular dynamics, wire electric explosion method, energy- dispersive analysis.

Tvardovskiy A.V.
General phenomenological approach for the description of adsorption and absorption equilibria – page 321
Abstract: Up to the present time, the construction of a general theory of the equilibrium adsorption is a very urgent task. In the present paper, a general phenomenological approach is developed to describe both adsorption and absorption equilibria. It was shown that under certain assumptions, the resulting equation transforms into the well-known classical Henry, Langmuir, Brunauer-Emmett-Teller equations with constants having a clear physical meaning. Thus, the constant in the Henry equation is determined by the temperature, the specific surface of the adsorbent, the size of the adsorbate molecules, the molar mass of the adsorbate and the isosteric heat of adsorption (the energy of interaction of the adsorbate molecules with the surface of the adsorbent). In the derived Brunauer-Emmett-Teller partial equation, in contrast to the classical version, a clear dependence of the equation constant on the specific physical characteristics of the adsorption system is indicated for the first time. It is determined by the concentration of adsorbate molecules in the liquid phase at the temperature under consideration, the concentration of adsorbate molecules during the formation of a dense monolayer on the surface of the adsorbent, the energy of interaction of adsorbate molecules with the
surface of the adsorbent and the heat of condensation. The presented approach can serve as a basis for modeling a variety of adsorption and absorption phenomena, including adsorption on microporous adsorbents.
Keywords: adsorption, adsorbent, absorption, thermodynamics of phase equilibria, Henry equation, Langmuir equation, Brunauer–Emmett–Teller equation.

Yurov V.M., Portnov V.S., Mausymbayeva A.D.
Thickness of the surface layer of as-class hydrocarbons – page 331
Abstract: The aim of the work is to build a model of the surface layer of objects (crystals) and to elucidate the role of surface energy in physical processes occurring in the nanoscale region. Frame hydrocarbons of the adamantane type, which have a highly symmetrical diamond-like structure, were chosen as objects. On the basis of an empirical model, the thickness of the surface layer and the surface energy of framework hydrocarbons were determined for the first time. In practice, this is very important, since all physical and chemical processes significant in operation occur through the surface layer. For adamantane, the thickness of this layer is 21.6 nm, and for diamond it is 8.2 nm, that is, they represent a nanostructure. Such a difference in the thickness of the surface layer of the two types of structures causes their sharp difference in their properties, in particular, in their surface energy, which determines their mechanical properties. For adamantane, the surface energy is 378.7 mJ/m2, and for diamond it is 9400 mJ/m2. In practice, researchers have found that under shock-wave action, the degree of adamantane→diamond transformation is almost 30%. The work of adhesion for frame hydrocarbons is 400–500 mJ/m2, and internal stresses are 35–45 MPa, which in the surface layer lead to a decrease in adhesive strength and the inverse Hall-Petch effect.
Keywords: surface layer, nanostructure, surface energy, atomic volume, size effect, hydrocarbon, adamantane, diamond, empirical model.

3. FIRST PRINCIPLES AND ATOMISTIC MODELING – page 342

Andre E., Tsirulev A.N.
Modeling of entangled states in qubit clusters – page 342
Abstract: The model of universal quantum computation, which uses quantum circuits consisting of one-qubit and two-qubit logic elements, is implemented in several existing quantum-computing devices. In the last decade, the idea of using multiqubit gates has become very relevant, since this, in the future, will reduce the noise level of quantum circuits. The main resource of quantum computing is the entanglement of individual qubits that form a cluster. Despite the actuality of this issue, so far only a few examples of the simplest logic elements with entanglement are considered in theory for a system of three qubits (Toffoli element and double controlled NOT). This work is devoted to mathematical modeling of the entangled states of quantum systems composed of several qubits. A mathematical method is proposed for the exact or approximate construction of Hamiltonians generating the required unitary transformations. It turns out that the approach based on the representation of Hamiltonians and unitary transformations in the Pauli basis is the most suitable in this context for two reasons: firstly, the Pauli basis forms the Lie algebra of the corresponding unitary group; secondly, there are only real coefficients in the decompositions of Hamiltonians and state density operators in this basis. The method is considered in detail on the example of a three-qubit cluster driven by a ternary Hamiltonian to obtain the Greenberger-Horn-Zeilinger entangled state. For this system, the thermal state is also studied and the corresponding density operator is obtained.
Keywords: quantum gate, quantum entangled state, unitary transformation, decomposition of Hamiltonian, Pauli basis, Greenberger-Horn-Zeilinger state.

Blinova A.A., Blinov A.V., Pirogov M.A., Ogurkov K.A., Maglakelidze D.G., Yakovenko A.A.
Computer quantum chemical modeling of the interaction of calcium phosphate with amino acids – page 352
Abstract: In this work, a quantum-chemical modeling of the process of interaction of calcium phosphate with amino acids was carried out. Within the framework of the quantum chemical modeling, the total energy of the molecular complex E, the energy difference between the amino acid molecule, and the «calcium phosphate – amino acid» system ∆E, the energy of the highest occupied molecular orbital EHOMO, the energy of the lowest free molecular orbital ELUMO, and the chemical rigidity of the system η were calculated. In this work, 8 essential proteinogenic amino acids were considered as stabilizers. As a result of the data analysis, it is found that all the presented interactions are energetically favorable: ∆E > 3370 kcal/mol, and the chemical rigidity of these interactions is in the range from 0,049 to 0,090 eV. Based on the obtained data, the most stable and energetically favorable interaction is the «calcium phosphate – Lys» system (∆E = 3395,848 ± 0,151 kcal/mol, η = 0,085 ± 0,006 eV). To confirm the data obtained, the samples were examined by IR spectroscopy. It has been established that the interaction of the amino acid lysine with the surface of a calcium phosphate particle occurs when oxygen is bound to amino groups in the lysine molecule.
Keywords: quantum chemical modeling, calcium phosphate, valine, leucine, isoleucine, methionine, threonine, lysine, phenylalanine, tryptophan, chemical rigidity, IR spectroscopy method, total energy of the molecular complex.

Vasilyev S.A., Puitov V.V., Talyzin I.V., Samsonov V.M.
Comparative molecular dynamics simulation of synthesis of silver nanoparticles from the gas phase – page 362
Abstract: A comparative molecular dynamics simulation of the gas-phase synthesis of Ag nanoparticles is carried out employing two different types of many-particle potentials of the interatomic interaction: a potential corresponding to the embedded atom method and the tight-binding potential. The initial temperature was varied from 1000 to 3000 K, and then it gradually decreased to 77 K, which corresponded to the temperature of liquid nitrogen. The results obtained using alternative force fields are consistent with each other, but, at the same time, they significantly differ both in the dynamics of evolution of the system and in the
obtained final configurations of nanoparticles. Increasing the cutoff radius of the tight binding potential significantly changes the rate of the nanoparticle formation. However, an increase in the cutoff radius when using the embedded atom method does not affect the evolution of the system. The configurations obtained as a result of simulation using the embedded atom method are characterized by a smaller size and a shape close to spherical, while when using the tight binding potential, larger nanocrystals with an elongated shape are formed.
Keywords: silver nanoparticles, gas-phase synthesis, embedded atom method, tight binding potential, molecular dynamics.

Veresov S.A., Savina K.G., Veselov A.D., Serov S.V., Kolosov A.Yu.., Myasnichenko V.S., Sdobnyakov N.Yu.., Sokolov D.N.
To the problem of investigating the processes of structure formation in four-component nanoparticles – page 371
Abstract: Various types of configurations of the Au-Cu-Pd-Pt four-component nanosystem, including complex core-shell structures, have been studied. The Monte Carlo method was used as a simulation method, the interatomic interaction was described by the tight-binding potential, i.e. the Gupta potential. According to the results of a series of computer experiments, it was found that four-component nanoparticles of this system do not tend to form a core-shell structure, even though gold atoms have an increased surface segregation. The melting temperatures for the nanosystems under study have been determined. The obtained values are in the range from 1100 K to 1250 K and weakly depend on the composition of nanoparticles (the ratio of the number of atoms). A stoichiometric composition based on these metals was found, for which, during cooling, an FCC crystal structure with inclusions of the HCP phase is formed. However, no distinctive features in the nature of segregation for this stoichiometric composition have been established. All considered stoichiometric compositions in the studied temperature range were stable with respect to decomposition.
Keywords: Monte Carlo method, tight-binding potential, four-component nanoparticles, structure formation, melting temperature, stability.

Gafner Yu.Ya., Ryzhkova D.A.
Simulation of the synthesis process Cu-Au nanoparticles from a gas medium: general analysis – page 383
Abstract: The process of synthesis of CuAu nanoclusters from a high-temperature gas phase was simulated. The molecular dynamics method was used. 91124 Cu and Au atoms were used as the initial configuration. The atoms were arranged randomly in space, the average distance between them was 30 Bohr radii. The set of parameters was chosen in such a way as to simulate the conditions of the inert gas condensation. This system was cooled with a thermal energy removal rate of 108 K/s. Based on the data obtained, conclusions were drawn about the main stages of the evolution of the model system. It is shown that the initial stage of synthesis consists of five different stages, which gradually lead to the formation of primary spherical nanoparticles of the CuAu binary alloy. At the final stage, the eventual transformation of the formed primary nanoparticles takes place. The initial atomic atmosphere almost completely disappears and spherical binary nanoparticles are formed, a characteristic feature of which is the displacement of gold atoms to the surface.
Keywords: nanotechnology, nanopowders, computer simulation, tight-binding model, nanoparticles, copper, gold.

Gafner Yu..Ya.., Ryzhkova D.A.
Analysis of the chemical composition of Cu-Au nanoparticles during simulation of the process of gas-phase synthesis – page 391
Abstract: The process of synthesis of CuAu nanoclusters from a high-temperature gas phase was simulated. The molecular dynamics method was employed, 1124 Cu and Au atoms were used as the initial configuration. The computer model of synthesis from the gas phase was based on an experimental setup located at the Budker Institute of Nuclear Physics SB RAS. On the basis of the data obtained, conclusions were made concerning the real chemical composition of clusters at the final stage of formation. It is shown that clusters larger than 400–500 atoms adhere to the given target ratio. The maximum deviations from the target ratio were recorded only for atomic vapor of stoichiometric composition. In other cases, with a reduction in the percentage of gold atoms in the initial pair, the deviations of clusters from the required composition decreased. It was determined that the reason for this was a different crystal structure of the nanoparticles obtained by modeling.
Keywords: nanotechnology, nanopowders, computer simulation, tight-binding potential, nanoparticles, copper, gold.

Gafner Yu..Ya.., Ryzhkova D.A.
Influence of gold atoms on the structure of Cu-Au nanoparticles at simulation of the process of gas-phase synthesis – page 399
Abstract: The article considers the process of formation of binary Cu-Au nanoclusters with different target composition from a high-temperature gaseous medium. The molecular dynamics method was used. The main attention was paid to studying formation of the crystal structure in such clusters and determination its type. It is shown that an increase in the percentage of gold atoms in the primary gaseous medium significantly affects the formation of the internal structure of simulated nanoparticles. With a relatively small increase in the proportion of gold atoms, there is a complete disappearance of clusters with the fcc structure. The formation of nanoparticles with, as a rule, five-particle symmetry is observed. In this case, the Dh configuration prevails. If both precursors are evaporated at the same rate, then an increase in the percentage of gold atoms in the gas mixture leads to the fact that CuAu clusters are often unable to form any clearly distinguishable crystalline form, due to which approximately every fourth cluster was fixed in the amorphous state. We concluded that the cause of this phenomenon may be the separation of atoms of different types, which is typical for binary nanoparticles of the studied chemical composition.
Keywords: nanotechnologies, nanopowders, computer simulation, tight-binding model, nanoparticles, copper, gold.

Kartashynska E.S.
Temperature dependences of the molecular area of surfactant 2D monolayers at the air/water interface – page 408
Abstract: The dependences of the molecular area (Ac) at the onset of the transition from the liquid-expanded to liquid-condensed (LE-LC) phase for 2D surfactant monolayer on the temperature and chain length are considered for seven surfactant classes at the air/water interface. A thermodynamic model of the amphiphilic monolayer behavior (taking into account the nonideality of mixing entropy) is used to evaluate Ac, as well as a quantum chemical approach that allows an assessment of the thermodynamic and structural parameters of surfactant associates. The calculated Ac values adequately reflect the experimental temperature dependence for the considered phase transition: the temperature increase leads to a decrease of the area per surfactant molecule with the fixed chain length and vice versa lengthening of the surfactant carbon chain at a fixed temperature results to the Ac value increase. The average values of the slope in the Ac = f(T) dependences for the regarded surfactant classes are in the range of 0,57-1,32 Å2/°C. The estimation of the (dAc/dn)T value shows that the best agreement of the calculated and available experimental data is achieved for saturated carboxylic acids and dialkyl-substituted melamine. The obtained results demonstrate applicability of the proposed approach for predictive purposes.
Keywords: 2D monolayer, clusterization Gibbs energy, unit cell, phase transition, thermodynamic model.

Kolosov A.Yu.., Mitinev E.S., Taktarov A.A., Myasnichenko V.S., Bazulev A.N., Sdobnyakov N.Yu..
Regularities of structural transformations in bimetallic Pd-Pt nanoparticles – page 419
Abstract: The processes of melting and crystallization of bimetallic Pt- and Pd-based nanoparticles have been studied by the method of molecular dynamics. The possibility of obtaining stable nanoparticles containing 3000 and 4000 atoms in the temperature range from 500 K to 1600 K is established. The concept about the possibility of fixing the temperatures of starting and ending of the phase transition for melting and crystallization is confirmed which was put forward earlier for monometallic platinum and palladium nanoparticles. The analysis shows that during the cooling of Pd-Pt nanoparticles with an initially uniform distribution of components, formation of a mixed structure with a surface monolayer of Pd atoms is observed. The possibility of structural segregation in bimetallic Pd-Pt nanoparticles containing 3000 and 4000 atoms is shown. At the same time, these two sizes correspond to different scenarios. For bimetallic nanoparticles with 3000 atoms, local zones are mainly polyhedral, and for bimetallic nanoparticles containing 4000 atoms, formation of extended band structures is observed.
Keywords: molecular dynamics method, bimetallic nanoparticles, platinum, palladium, segregation, structural transformations, stability.

Komarov P.V., Malyshev M.D.
Investigation of welding process of vitrimer-based material: meso-scale simulation – page 435
Abstract: A self-healing epoxy material is considered, based on bisphenol A diglycidyl ether and atricarboxylic fatty acid hardener, belonging to a new class of polymers called vitrimers. The res toration of the integrity of such systems in the case of a damage occurs due to the exchange reaction of covalent bonds between the comonomers forming a polymer network. In our previous work, we have developed a model of this material based on the method of reactive dissipative particle dynamics. In this work, we apply our model to study the welding process of vitrimer samples cut into two parts. The control of the integrity of the structure of the systems was carried out using a topological analysis by calculating the distributions over the lengths of simple cycles and the density of the number of load-bearing circuits. It has been shown that the rate of restoration of the integrity of the systems is determined by the concentration of the catalyst and the degree of crosslinking of the polymer. The results obtained also indicate that in the case of a high degree of crosslinking of the polymer, as well as a low catalyst concentration, the structure of the system is highly inhomogeneous.
Keywords: vitrimers, network polymers, mesoscopic modeling, dissipative particle dynamics, bond exchange reaction.

Kuznetsov Yu..A., Lapushkin M.N.
Electron-stimulated desorption of rubidium atoms adsorbed on the surface of gold-rubidium intermetallide – page 450
Abstract: The calculation of the density of states of various thicknesses of the 2D-layers of the intermetallic compound RbAu has been carried out. 2D-layers of intermetallic compound RbAu are simulated by supercells RbAu (111) 2×2×2. For a monolayer 2D-layer of an intermetallic compound RbAu the presence of a bandgap with a width of 2,70 eV has been established. An increase in the thickness of the 2D-layers of the intermetallic compound RbAu to three monolayers showed a decrease in the bandgap to 0,80 eV. A further increase in the thickness of the 2D-layers of the intermetallic compound RbAu leads to the disappearance of the band gap, which indicates a semiconductor-metal transition for the 2D-layer of the intermetallic compound RbAu with a thickness of four monolayers. The valence band of the 2D-layer of the intermetallic compound RbAu is formed mainly by Au 5d
electrons, with an insignificant contribution from Au 6s and Au 6p electrons. The conduction band of RbAu is formed mainly by Au 6p electrons with an insignificant contribution of electrons Rb 5s.
Keywords: electronic structure, ab initio calculation, intermetallic compounds, rubidium auride, 2D-layer.

Kurbanova E.D., Polukhin V.A.
Strength and functional characteristics of hexa and pentagonal 2D materials. Hydrogen – page 458
Abstract: An analysis of synthesized unique two-dimensional 2D materials with nanolayer hexagonal and pentagonal structures (based on carbon, silicon, tin, binary compounds CN2, BN2, PdSe2 and ternary compounds – BCN, CNP, PdSSe, Zn2C2P2) was carried out. The synthesis of these materials was performed by the chemical vapor deposition or metal epitaxy on pre-prepared substrates. The strength and functional characteristics (electronic, optical) of the created models were also analyzed using the DFT theory in the form of triple monolayers with double-sided deposition of hydrogen on the surface of the p-Si2C4 monolayer: hydrogen/p-Si2C4/hydrogen. It was found that the p-Si2C4-4H layer with its two-sided hydrogen adsorption and good properties was the most dynamically stable. This article also presents relatively recently obtained hexa- and pentagonal two-dimensional materials not only for the elements C, Si, Ge, B, but also for Cu1–xNix, Ti1–xNix alloys and Bi1–xSbx, CN2, BN2, PdSe2, etc. compounds. So, with the new unique materials created – the synthesis of superstrong, thermostable nanocomposites, superconducting layered composites (based on Bi, Hg and Sb), prospects are opening up for the development of nanoelectronics, spintronics, computer technology, as well as the creation of portable strain gauges, pressure sensors, gas sensors and dialysis catalysts for water dialysis with the release of hydrogen and oxygen.
Keywords: hexagonal and pentagonal structures of 2D materials, material modeling, mechanical properties, catalytic properties.

Myasnichenko V.S., Sokolov D.N., Bazulev A.N., Nepsha N.I., Ershov P.M., Sdobnyakov N.Yu..
Construction of a lattice Monte Carlo model of layer-by-layer growth of bimetallic nanoparticles – page 468
Abstract: Based on the Metropolis software, a lattice statistical model of the layer-by-layer growth of bimetallic nanoparticles has been implemented. As an example, this paper analyzes two types of lattices: fcc and decahedral. On their basis, the growth of free Au-Ag nanoparticles is modeled in three modes that differ in growth stages: 3, 4, or 7 bimetallic layers are added. The interatomic interaction is set by the tight-binding potential, however, the constructed model does not exclude the possibility of using other modifications of the proven many-particle potentials. The change in the specific potential energy of entire nanoparticles and gold atoms during layer-by-layer growth is analyzed. The dependence of the number of mixed bonds on the layer number is studied for the entire nanoparticle and for the gold subsystem.
Keywords: computer experiment, Monte Carlo method, Metropolis scheme, layer-by-layer growth, bimetallic nanoparticles, mixed bonds.

Pan’kin N.A.
Molecular dynamic simulation of heating of titanium nanoclusters – page 479
Abstract: The melting of titanium nanoclusters Tin (n = 3599, 28725, 97045) with different heating rates (from 0,1 to and 10,0 TK/s) was studied by the molecular dynamics method. Molecular dynamics simulation was carried out using the LAMMPS program on a multiprocessor computer. A many-particle potential of interatomic interaction was used. The crystal structure of a titanium nanocluster upon heating passes into the liquid phase through the formation of a system of atoms (islands) with an ordered local environment near the melting point. The appearance of the latter is due to the non-equilibrium of the simulated heating process – the system does not have time to relax to an equilibrium state for a chosen temperature. The melting temperature was taken as the average value between the temperatures of the beginning and finishing of the phase transition process. The temperature of the beginning of melting corresponded to the state of completion of formation of individual islands. At the end of melting, the nanostructure is characterized by a completely disordered structure. It is noted that the melting temperature increases with the size of the nanoparticle and the rate of its heating. The limiting temperatures of the considered phase transition (at N → ∞) are significantly lower than the melting temperature of the bulk titanium.
Keywords: titanium, nanocluster, melting point, heating rate, structure, islands, molecular dynamics method.

Ryzhkova D.A., Gafner S.L., Gafner Yu..Ya.., Cherepovskaya A.A.
Molecular dynamics study of the size limit of the transition of silver nanoclusters with an initial amorphous substructure into FCC phase – page 490
Abstract: Silver nanoclusters with diameter of 3,0 to 7,0 nm were studied by the molecular dynamics method using the tight binding potential TB-SMA (second moment approximation of tight-binding potential). A search was made for the stability limits of structural modifications of these nanoclusters for determination of the size limit of the thermally induced structural transition from the initial amorphous morphology to the fcc phase. The new data were compared with the results of previous studies for Ag nanoparticles up to 2,0 nm in size with initial fcc and amorphous structures. It is shown that the studied nanoclusters can be conditionally divided into three categories. The first one (N < 100 atoms) is characterized by partial preservation of the original morphology. For the second one (d < 4,0 nm), there is competition between the icosahedral and decahedral structures. And for the thirds (d > 4,0 nm), the mixed fcc/hcp phase predominates. In this case, the size limit of the transition from the initial amorphous morphology to the structure characteristic for the bulk matter is a diameter of about 7,0 nm.
Keywords: nanoclusters, silver, computer simulation, structure, tight binding, phase transitions, structural stability.

Savina K.G., Galuzin I.R., Kolosov A.Yu.., Bogdanov S.S., Veselov A.D., Sdobnyakov N.Yu..
On the processes of segregation and stability of bimetallic nanoparticles Ni@Ag and Ag@Ni – page 499
Abstract: This work studied bimetallic nanoparticles Ni@Ag and Ag@Ni with the total number of atoms 4000 by the molecular dynamics method using the tight-binding potential. The pattern of segregation and structural formation is established and its characteristics are described. Based on the analysis of the behavior of the calorie curves of the potential part of the internal energy, the melting and crystallization temperature was determined. The data obtained suggest that the processes of segregation in Ni@Ag and Ag@Ni nanoparticles are associated with the nanoparticle stability. The silver shell loses its stability above 900 K, while the nickel core remains solid and retains its structure. At the same time, in Ni675@Ag3325 nanoparticles the processes of the surface segregation of the nucleus atoms were less pronounced, whereas in Ag675@Ni3325 nanoparticles silver atoms actively segregated onto the surface of the nanoparticle. The features and fundamental differences in the processes of melting and crystallization of these nanosystems, as well as the temperature ranges of their stability, are analyzed. The relationship between the degree of intensity of segregation processes of nanoalloys during modeling and the stability of these systems is shown.
Keywords: molecular dynamics method, bimetallic nanoparticles, nickel, silver, segregation, structure formation, stability, core-shell.

4. PHYSICAL AND CHEMICAL BASES OF NANOTECHNOLOGIES – page 512

Belyakova R.M., Kurbanova E.D., Polukhin V.A.
Alloying and strain hardening of high-entropy membrane storage nano and crystalline alloys – page 512
Abstract: The article presents both molecular dynamics calculations of binary Fe–Ni alloys and experimental studies of Ti and Co alloyed nanocrystalline alloys with a B2–Ti(Fe, Co) matrix structure as well as bcc-(Nb, Ti) and B2– eutectic phases Ti(Fe, Co). The structures of membrane alloys based on Fe–Ni (arrangement of atoms in coordination polyhedra and interatomic distances between atoms), as well as the kinetics of hydrogen – diffusion and permeability have been studied. It is shown that in the membranes of alloyed alloys with the substitution of Ni for cobalt Fe35-XCoXTi35Nb30, with an excess of Fe than for cobalt, mechanical brittleness is manifested in the B2–TiFe phase, and the plasticity of the B2 phase also decreases. At the same time, the resistance to an increase in hydrogen absorption is also weakened, up to mechanical destruction of membranes, so that in high-entropy alloys Fe0,2Ni0,2Cr0,2Co0,2Mn0,2, Fe0,2Co0,2Cr0,2 Ti0,2Al0,2 Fe and Co in equal parts. Other intermetallic alloys are also promising, having more complex compositions with high or moderate entropy, for example, Zr0,2Ti0,2Nb0,2V0,2Co0,2 and Zr0,2Ti0,2Ta0,2V0,2Co0,2, in addition to hydrogen evolution, also have storage properties. Within the framework of molecular dynamics, the effect of strain hardening of membrane HEA alloys is experimentally presented – the mechanism of synergy with multiple deformation. As a result of such hardening, a partial transformation of the austenitic phase into a
martensite phase occurs with the formation of twinning in their fcc/hcp grains and the formation of a two-phase matrix structure.
Keywords: nanocrystalline alloys, modeling, alloying, work hardening, matrix structure, eutectic phases, high-entropy alloys, austenite, martensite, membranes, hydrogen, hydrides.

Bogdanova E.A., Skachkov V.M., Nefedova K.V.
Preparation of biocomposites based on nanoscale hydroxyapatite with titanium compounds – page 521
Abstract: The article discusses the possibility of obtaining a hardened composite material with a porous structure based on nanostructured hydroxyapatite (HAP) synthesized by precipitation from a solution. The new material by the mechanochemical synthesis of HAP with reinforcing additives of titanium compounds was obtained. The synthesized samples are certified using some modern physico-chemical methods of analysis. The influence of the qualitative and quantitative composition of the composite on the sintering processes, porosity, strength characteristics, the degree of dispersion and morphology of the studied samples is shown. It has been experimentally established that a sample based on hydroxyapatite, reinforced with non-stoichiometric titanium dioxide of the composition Ca10(PO4)6(OH)2 – 15%TiOx has the maximum strength characteristics and constant composition. The composite material, having a dense uniform structure with a high degree of crystallinity and a developed porosity, is a promising material for further research in order to introduce it into medical practice. A patent application has been filed on the developed composite material.
Keywords: hydroxyapatite, titanium oxide, titanium compounds, composite biomaterials, crystallinity, microhardness.

Bolotov A.N., Novikova O.O., Meshkov V.V.
Viscometric studies in the process of synthesis of magnetic lubricant nano-oils – page 531
Abstract: In the field of tribology, magnetic lubricating oils are promising, in which polymers are used to increase their colloidal stability, but their use is limited by the low magnetization of the colloid. It is possible to increase the magnetization of nanooils by synthesizing polymer shells directly on the surface of magnetic particles in the process of obtaining nanooils. The features of the technology for the synthesis of magnetic lubricating nanooils with polymeric solvation shells on particles, which protect them from coagulation, are described. Polymerization of hydroxy acid molecules proceeds by the mechanism of polycondensation on the solid surface of magnetite. The viscosity of the magnetic colloid increases due to the increase in the thickness of the solvate shell. Proceeding from this, a differential equation is proposed, which shows the dependence of the growth rate of the colloid viscosity on the rate of the polycondensation reaction. An experimental verification of the equation showed that it is fulfilled with an accuracy up to 8%. The resulting equation makes it possible to determine an important thermodynamic characteristic – the activation energy of the process of synthesis of polymer shells on the surface of dispersed particles. For calculations, it is necessary to
know the rate of change in the viscosity of a colloid with a dispersion medium without a monomer (hydroacid). Therefore, in the process of the polymer synthesis, samples of the intermediate magnetic colloid of a small volume are taken, which are used to determine the viscosity of the colloid and dispersion medium containing monomers. Then the viscosity of the colloid with a pure dispersion medium is found, which is necessary for calculating the activation energy of the polycondensation reaction. According to estimates, the error in determining the activation energy does not exceed 11%. In practice, using the values of the activation energy of polymerization, it is possible to carry out a purposeful choice of the optimal temperature-time regime for stabilizing the magnetic colloid in order to obtain a magnetic nanooil with the required viscosity and aggregative stability characteristics. Experimental studies were carried out on specially designed instruments for assessing the colloidal stability and dynamic viscosity of magnetic colloids.
Keywords: colloidal systems, magnetic lubricating nanooils, viscosity, colloidal stability, activation energy of polymerization.

Bolotov A.N., Novikova O.O.
The effect of the nanodisperse phase of magnetic oils on their lubricating properties – page 545
Abstract: The work is devoted to the study of processes occurring in the boundary lubricant layer, in which nanodisperse magnetic particles play a decisive or significant role. The friction between metal surfaces with lubricated oils of different concentrations of the magnetic nanodisperse phase was studied. The dispersion medium of magnetic oils consisted of liquids with various physico-chemical properties: dioctylsebacinate, triethanolamine, polyethylsiloxane. It has been shown that the wear intensity of surfaces with a hardness higher than that of nanoparticles monotonically increases with increasing the particle concentration, and wear is abrasive in nature. The wear rate of softer materials passes through a minimum at a particle concentration of about 2 vol.%. Magnetic separation of large agglomerates in oil allows for some time to reduce the abrasive wear until they are formed again under friction conditions. It was not possible to identify the regularities of the influence of nanodispersed particles on the friction force, it is probably insignificant. Several examples of the indirect effect of nanodispersed particles on the boundary friction are considered. In all the examples, the determining role plays huge area of the active surface of particles per unit volume of oil. For example, under conditions of friction, atomic hydrogen can be actively formed during the chemical interaction of fatty acids with the surface. Atomic hydrogen accumulates in the subsurface pores and is crystallized there. The increased pressure in the pores created by hydrogen molecules leads to an increase in wear by the peeling mechanism. The established regularities of the influence of nanodispersed particles on the rate of formation of the boundary lubricant layer and the corrosion wear of surfaces caused by surface-
active additives in magnetic oil are of scientific interest.
Keywords: nanodisperse particles, magnetic oil, grease, friction, wear.

Vostrov N.V., Solnyshkin A.V., Morsakov I.M., Belov A.N., Krylov P.N.
Investigation of the physical properties of PVDF thin films obtained by 4D printing – page 561
Abstract: In this work, we searched for the optimal way to create ferroelectric nanostructured composite materials based on 4D-printed polyvinylidene fluoride polymer films. Method fused deposition modeling allow using polyvinylidene fluoride and its copolymers not only in microelectronics as pyroelectric and piezoelectric sensors, as well as creating dynamic memory elements, organic solar cells and used in robotics. At the first stage of the work, the authors were selected optimal extrusion parameters for the manufacture of a thread from powder and granules. The next stage of the work included the analysis and determination of printing parameters by the method of layer-by-layer filament deposition to obtain the best quality of polymer films. Using scanning electron microscopy, the existence of two phases, a polar β-phase and a nonpolar α-phase, is shown, where the crystalline phase is observed in the form of lamellar crystals chaotically oriented in the α-phase matrix. Pyroelectric measurements performed by the dynamic method showed the presence of a noticeable pyroelectric response in polyvinylidene fluoride films obtained using additive technologies, bypassing the orientation extraction stage. The calculation of the pyroelectric coefficient gives values corresponding to the values of the pyroelectric coefficient for polyvinylidene fluoride samples obtained by traditional methods.
Keywords: composite, polymer ferroelectric, additive technologies, 4D printing, 3D printing, spontaneous polarization, piezoelectric effect, pyroelectric effect, scanning electron microscope.

Guseva O.S., Malyshkina O.V., Mitchenko A.S.
Effect of modifiers on the barium niobate-calcium ceramics structure – page 572
Abstract: In this work, the ceramic samples Са0,3Ba0,7Nb2O6 pure and with modifying additives (5%) SrTiO3, KTaO3 or LiTaO3 were obtained by solid-phase synthesis. All studied compositions of ceramics revealed the presence of large and small grains. It is shown that the addition of LiTaO3 to the composition of Са0,3Ba0,7Nb2O6 ceramics reduces the grain size by an order of magnitude, while the addition of SrTiO3 leads to an elongation of the grain shape. Based on the analysis of the elemental composition, it was found that the introduction of modifiers into the composition of Са0,3Ba0,7Nb2Oreduces the excess of oxygen in the structure of tetragonal tungsten bronze, compared to unmodified Са0,3Ba0,7Nb2O6 ceramics. The maximum on the temperature dependence of the permittivity is practically independent of the type of modifier and is located in the range of 279-285°C. This is 60 degrees higher than the Curie temperature of the Са0,3Ba0,7Nb2O6 single crystal. Regardless of the measurement temperature, Са0,3Ba0,7Nb2O6 + 5%SrTiO3 material has the maximum value of the permittivity. Whereas the minimum value of the permittivity at room temperature has the Са0,3Ba0,7Nb2O6 + 5%LiTaO3 sample, and at the Curie point, the Са0,3Ba0,7Nb2O6 sample.
Keywords: piezoelectric ceramics, barium-calcium niobate, lead-free materials, modifiers, grain structure, permittivity.

Gyrdashova O.I., Stepanov A.E., Naumov S.V., Shkerin S.N.
Effect of synthesis conditions on the formation of Y3-xLaxFe5-yO12+δ/La1-xYxFe1-yO3 composite – page 583
Abstract: Glass-like composite materials with high oxygen conductivity values were obtained by growing from a homogeneous melt by the method of non-melting zone melting. A complex architecture of the composite is observed: the main phase is highly defective in cationic and anionic sublattices Y3-xLaxFe5-yO12+δ with a garnet structure, inside which the germination of filamentous crystals La1-xYxFe1-yO3 with a perovskite structure is observed. The effect of the method of synthesis of polycrystalline precursors used as raw materials for the production of the melt on the formation of the structure of composites La1-xYxFe1-yO3/Y3-xLaxFe5-yO12+δ is investigated. The composite obtained from the precursor formed by the formate method contains ~87 mol.% of the main phase.The composite obtained from the precursor formed by the self-propagating high-temperature synthesis is ~76 mol.% of the garnet phase. The obtained composites have a certain growth direction of the main phase Y3-xLaxFe5-yO12+δ <100>.
Keywords: yttrium ferrite, garnet structures, synthesis, precursors, morphology, composites, oxygen conductivity.

Devitsky O.V.
Structure and composition of thin GaAs1-x-yNxBiy films produced by pulsed laser deposition – page 593
Abstract: Uniaxial cold pressing was used to fabricate GaAs0,9Bi0,1 targets with 10% Bi content. Thin
films of GaAs1-x-yNxBiy onto a GaAs (100) substrate were obtained from the formed GaAs0,9Bi0,1 target
by pulsed laser deposition in an argon-nitrogen gas atmosphere, and their structure and composition
were studied. It is shown that on the surface of the film there are predominantly small microdroplets
with a diameter of less than 0,5 μm, formed by Bi atoms. Large microdroplets with a diameter of 2 to 6
μm consist partly of Bi and Ga. No microdroplets formed only from Ga were found. It is noted that
small Ga microdroplets are adsorbed on the surface of large Bi microdroplets without forming a GaBi
alloy. It was also found that the formation of Bi microdroplets also occurs due to the segregation of Bi
atoms on the film surface. The energy-dispersive spectroscopy data make it possible to characterize
the resulting thin films as GaAs0,995N0,015Bi0,03. The mean square roughness of the film surface was 12,2
nm. The resulting GaAs0,995N0,015Bi0,03 film has a polycrystalline structure. An analysis of the X-ray
diffraction data showed that the film grew according to the Volmer-Weber law, when islands are
nucleated and their sizes subsequently increase. The nuclei are most likely formed by GaAs, GaN,
GaAsN, GaAsBi, and GaAsNBi. The calculated full width at half height for GaAs0,995N0,015Bi0,03 was –
0,8656ʺ, and the average crystallite size was 1,6 nm.
Keywords: thin films, III-V-N-Bi, GaAs1-x-yNxBiy, pulsed laser deposition, diluted nitrides, diluted bismuthides.

Zajogin A.P., Trinh N.H., Malets M.A., Patapovich M.P.
Peculiar properties of methods for obtaining amorphous nanofilms for creating gas-sensitive sensors under the action of laser double pulses on the surface of a target containing tin – page 602
Abstract: A layer-by-layer analysis of metals and alloys has been carried out, and the possibility of deposition of nanofilms containing tin in their composition on various types of surfaces (metal, glass) under the action of dual laser pulses on a target in an air atmosphere has been studied. The experiments were carried out using the laser two-pulse multichannel atomic emission spectrometer LSS-1. The advantages of the pulsed laser deposition as a method for producing clusters and fractals are: versatility in relation to the material, the ability to exclude impurities, the flexibility of the method, and the ability of controlling the formation of film structures. The performed spectroscopic studies of the laser plasma formed by the action of two successive pulses on a target illustrate the development of methods for obtaining nanoclusters of various chemical elements. This method can be used to obtain nanofilms of not only pure metals, but also composite alloys. The possibility of obtaining nanofilms for creating gas-sensitive sensors is shown.
Keywords: double laser pulses, laser plasma, layer-by-layer analysis, deposition of thin films, nanopowder technologies, multichannel atomic emission spectrometry.

Ivanov Yu..F., Klopotov A.A., Lopatin I.V., Ivanova O.V., Petrikova T.L., Petukevich M.S., Nikonenko E.L.
Phase formation in high-chromium steel under electron-ion-plasma treatment – page 609
Abstract: The surface alloying was carried out by single-cycle and multi-cycle (5 cycles «sputtering-irradiation», in each cycle the thickness of the titanium film 0,5 µm), i.e. high-speed melting of the system «film (Ti)/(steel AISI 310S) substrate» by pulsed electron beam. Nitriding (793 K; for 1, 3 and 5 hours) was carried out under conditions of realization of the elion (electron and ion) treatment mode. The isothermal cross sections of the ternary systems of the state diagram of the Cr – Fe – Ni – Ti – N alloy formed at different stages of the complex treatment of steel are considered. It is shown that (1) irradiation of steel by a pulsed electron beam is accompanied by the formation of a structure of high-speed cellular crystallization of solid solution based on γ–Fe; (2) nitriding of steel in the initial state is accompanied by formation of nitrides of iron Fe4N and chrome CrN with a total content of 79,8 wt.%; (3) pulsed electron-beam pre-irradiation of steel leads to a decrease in the rate of nitride formation during subsequent nitriding; the total nitride content of 53 wt.%; (4) regardless of the number of alloying cycles (titanium concentration in the surface layer) after five hours of nitriding in the samples formed a surface layer of nitrides of chromium and iron (1 cycle of doping) or nitrides of chromium and titanium (5 cycles of doping).
Keywords: complex electron-ion-plasma treatment, electron plasma component heating of samples, high-chromium steel, surface alloying, phase composition.

Kapustinа G.G., Leonenko N.A.
Mechanisms of laser impact on ultra-fine mineral medium – page 621
Abstract: The development of modern technologies for the complex extraction of valuable components from refractory ores and technogenic deposits is possible on the basis of the latest achievements of fundamental sciences, a combination of physicochemical, enrichment and metallurgical processes. The paper describes the results on the impact of laser radiation on mineral samples with ultrafine «non-recoverable» gold from silt ponds-settlers of alluvial deposits in the Far East. The object of research is the impact of a source of continuous laser radiation on samples of minerals, objects of alluvial deposits containing submetric and nanosized forms of gold that are not recoverable by traditional gravity methods. The purpose of this work was to study the processes of interaction of laser radiation with dispersed mineral media containing ultrafine gold and to determine the conditions for agglomeration of ultrafine gold. Electron microscopic images of the samples were obtained using a LEO EVO 40HV microscope (Carl Zeiss, Germany) equipped with an INCA-ENERGY energy-dispersive analyzer. A model is proposed that describes the processes at the boundary of heterogeneous phases. An analysis of the discovered effect of gold agglomeration made it possible to formulate technical solutions that were reflected in patents for inventions. The discovered effect of gold agglomeration made it possible to find technical solutions in the form of patents for inventions.
Keywords: laser-induced, ultrafine, colloid-ion, gold, gold-bearing mineral products, structural ordering, scanning electron microscopy.

Klychkov N.A., Simakov V.V., Sinev I.V., Shikunov D.A.
The effect of copper and zinc oxide additives on the electrical and gas-sensitive properties of tin dioxide composite layers – page 632
Abstract: Composite thin films based CuO:SnO2 and ZnO:SnO2 with different impurity concentrations was synthesized by sol-gel method by mixing sols. The films were annealed in oxygen-containing atmosphere at 550°C. A contact system was formed on top of the films by thermal evaporation of chromium, followed by deposition through a mask onto the sample. Based on the temperature dependence of conductivity for layers based on pure tin dioxide, a local maximum of conductivity is observed in the range of 250°C, which is probably due to the thermal activation process of oxygen desorption. Conductivity of SnO2 layers was decreased as the concentration of Cu dopant. 2% Cu additive reduces the long-term conductivity drift by an order of magnitude. Arguably it’s the consequence of occurrence the low mobility complexes created by copper atoms and oxygen vacancies. The best sensitivity to ethanol vapors in all concentration range was shown by 6%Zn doped samples. Accordingly, supplementations of Cu and Zn boost sensitivity of SnO2 layers to ethanol and decrease response time by its impact at 150-300°C range.
Keywords: sol-gel method, composite gas-sensitive layers, tin dioxide, conduction drift, gas sensor’s response time.

Korolkov O.E., Pakhomov M.A., Polyakov A.V., Valiev R.Z., Stolyarov V.V.
Effect of grain size and duty ratio on the mechanical behavior of titanium under tension with pulsed current – page 639
Abstract: The influence of a high-density pulsed current on the deformation behavior of titanium with different structure refinement is studied. A comparison of the features of the deformation curves has been carried out of coarse-grained and nanostructured commercial pure Ti Grade 4 under tension with the introduction of a pulsed current. A current of various duty ratio and densities was supplied from a pulse generator to a sample in the grips of a tensile testing machine. The microstructure of a coarse-grained titanium in the sample head and near the fracture region in the longitudinal section was studied by optical microscopy. To study the microstructure of nanostructured titanium foils, the transmission electron microscopy was used. The electroplastic effect in the studied materials manifested itself in the tensile curve in the form of separate downward stress jumps. Under the same regimes of high-duty ratio pulsed current, the amplitude of stress jumps in the coarse-grained titanium is higher than in the nanostructured titanium. For a low duty ratio current the stress jumps are the same in the plastic region. A high duty ratio pulsed current in nanostructured titanium led to an anomalous hardening effect, the physical nature of which needs a further investigation. The used modes of the pulsed current did not lead to structural changes noticeable under optical magnification of the tensile samples, except for the disappearance of twins and the separation of impurity particles in the coarse-grained titanium. The fractographic fracture patterns of nanostructured titanium tested with and without current indicate ductile fracture without significant changes, which testified a minimal thermal contribution during the experiments.
Keywords: tension, titanium, nanostructure, electroplastic effect, pulsed current, fractography.

Kravchenko D.A., Medvedeva O.N.
Studies of the structure and properties of dental crowns made by selective laser melting and according to the technology of casting – page 652
Abstract: In recent times, 3D printing technologies are a young and actively developing production sector for many areas of economy, from aerospace and mechanical engineering to medicine. The obvious advantage of introduction of the additive technologies in medicine and in particular in dentistry is high accuracy in producing complex details, individually designed implants and prostheses for their maximum match with a place of injury or a substituted object, considerable reduction both the product materials and auxiliary materials usage. However, questions arise about the limits of applicability and reliability of the additive technologies with their active introduction. The properties of dental crowns made of nickel-chromium alloy NH-Dent NS vac and cobalt-chromium powder PR-KH28M6 were studied in this research. For the production of samples was used selective laser melting technology, which belongs to a number of additive technologies, and the casting technology in the mold. A comparative analysis of the microstructure of the samples, the surface profile and the Vickers hardness was carried out.
Keywords: additive technologies, medicine, dentistry, selective laser melting technology, selective laser melting, microstructure, surface profile, hardness of samples.

Masloboeva S.M.
Analysis of investigations of the lithium niobate charge LiNbO3:Mg synthesized on the basis of Nb2O5:Mg precursors of different genesis – page 662
Abstract: An analysis was made of studies on the preparation of a charge of lithium niobate used for growing crystals LiNbO3:Mg by the Czochralski method. The charge was synthesized on the basis of precursors Nb2O5:Mg of different genesis. The results of studies of the mixture by X-ray phase analysis, atomic emission spectrographic analysis, gas chromatography-mass spectrometry, mass spectrometry with inductively coupled plasma and laser ablation are presented. It has been established that in the studied systems, a uniform distribution of magnesium impurities in the charge is observed, which leads to the production of crystals of high optical quality with impurity distribution coefficients above unity. It has been shown that the presence of organic inclusions makes it possible to introduce more magnesium into the growing crystal. The results are of great importance in the technology of growing single crystals of lithium niobate when choosing a method for the synthesis of a charge in order to use the crystals obtained from it in specific areas of technology.
Keywords: niobium pentoxide, genesis, doping with magnesium, synthesis of lithium niobate charge, impurity distribution, single crystal, optical quality.

Nagaplezheva R.R., Orakova M.M., Kushkhova M.Yu.., Tseeva F.M., Mishaev H.A.
Influence of vacuum-plasma treatment modes on the surface photo-EMF of single-crystal silicon – page 671
Abstract: Plasma technologies in the last quarter of the twentieth century made a real scientific and technological revolution in microelectronics. Having come to the world of microelectronics technology as a necessary alternative to liquid etching, which had exhausted its resource by that time, plasma or «dry» technologies became the main tool for creating elements of electronic products. The 21st century, undoubtedly, began and proceeds under the sign of the improvement of such technologies in solid-state electronics. Plasma technologies include a set of methods for depositing thin and ultrathin layers on a semiconductor substrate, as well as a set of methods for dimensional etching of such layers with specified etching parameters. If we consider the methods of size etching using dry technologies, it should always be taken into account that the whole range of such methods is wide. Some methods, such as radical and plasma-chemical etching, imply a mild, purely chemical interaction of the plasma medium with the substrate material, resulting in the formation of a volatile etch product and its removal (pumping) from the plasma volume. Another group of «dry» methods includes methods of purely physical impact of high-energy plasma particles on the surface of the material and the removal of atoms from the surface only as a result of sputtering of the material. The surface photo-EMF method was used to study the real surface of single-crystal p-type silicon in the temperature range T = 289-473 K before and after plasma treatment. A significant difference was found in the surface electronic states spectra obtained by heating and cooling the samples. Heating leads to desorption of gases and dissociation of water molecules in the surface layer, which reduces the surface potential by an order of magnitude.
Keywords: plasma, photo-EMF, plasma surface treatment, silicon, surface electronic states.

Nalimova S.S., Shomakhov Z.V., Gerasimova K.V., Punegova K.N., Guketlov A.M., Kalmykov R.M.
Gas-sensitive composite nanostructures based on zinc oxide for detecting organic solvent vapors – page 678
Abstract: The paper shows the possibilities of using ZnO-Fe composite structures as gas-sensitive layers for detecting organic solvent vapors exemplifying on isopropyl alcohol. Composite structures were formed based on zinc oxide nanorods synthesized by the hydrothermal method, due to changes in their composition in a ferrous sulfate solution. The chemical composition of the surface was studied using X-ray photoelectron spectroscopy. It is shown that when using a ferrous sulfate solution with a concentration of 0,025 mol/l, iron and zinc atoms are observed on the surface. An increase in the concentration of the solution to 0,05 mol/l leads to the deposition of iron oxide particles on the surface of the nanorods. The study of some gas-sensitive characteristics was carried out at 250°C when exposed to isopropyl alcohol vapors in the concentration range from 200 to 1000 ppm. It was found that the response value of composite structures ZnO-Fe (0,025) exceeds the corresponding value for the zinc oxide nanorods, that may be due to the high content of oxygen vacancies in the composite sample.
Keywords: zinc oxide, gas sensors, composite nanostructures, X-ray photoelectron spectroscopy, organic solvent.

Nikolaychuk P.A.
Electrodeposition of silver nanoparticles for the development of electrochemical sensors: a short review – page 688
Abstract: In the present review the studies performed in the last two decades devoted to the electrodeposition of silver nanoparticles on the surface of carbon electrodes and their implementation in analytical chemistry are described. Usually graphite or glassy carbon electrodes (including screen-printed electrodes) are used, and the electrodeposition is performed from the solutions of potassium nitrate and silver nitrate during a few minutes. Silver nanoparticles or modified nanocomposites including silver nanoparticles are then immobilized on the surface of the electrodes, and obtained electrochemical sensors are capable to determine various compounds using different voltammetric methods with excellent selectivity and very good linearity range and precision. The described methods of analysis allow the determination of microgram quantities of hydrogen peroxide, glucose, cholesterol, methyl parathion, Pb2+ ions, chloramphenicol and metronidazole, doxorubicin, entacapone, tyrosine and tryptophan, lamotrigine, chromium (VI), antimony (III), trinitrotoluene, oligonucleotides and the bacterium Pseudomonas aeruginosa.
Keywords: silver nanoparticles, glassy carbon electrode, graphite electrode, electrodeposition, electroanalysis, voltammetry.

Skachkov V.M.
Features of dynamics change of properties of diffusion-hardening solder at various conditions – page 699
Abstract: A study was conducted of the change in the hardness of diffusion-hardening solder based on a low-melting gallium alloy: gallium-tin-zinc when interacting with the Spherical copper-tin alloy powder (SCTAP5) under normal conditions (temperature 25°C) and subjected to low-temperature (125°C) heat treatment. Mechanical properties are estimated by measuring microhardness at various time intervals. A differential thermal analysis was carried out, with calculations of thermal effects. The phases formed as a result of diffusion hardening were determined by X-ray phase analysis, and the parameters of the crystal lattices of the phases were compared under different conditions of diffusion hardening. It is shown that at different processing temperatures, different phases are formed – nanoscale intermetallic compounds, and with the help of a scanning electron microscope, the phase of tin released as a result of physicochemical transformations is found. It has been experimentally proved that diffusion-hardening solder without heat treatment gains hardness slowly, and after 60 days the hardness approaches to that of the sample subjected to heating, which also continues to gain hardness very slowly. Thus, it is shown that diffusion-hardening solders after six hours of low-temperature treatment have not yet reached physico-chemical equilibrium.
Keywords: composite diffusion-hardening solders, exothermic effects, properties, microhardness, differential thermal analysis, X-ray phase analysis.

Skachkov V.M., Pasechnik L.A., Medyankina I.S., Sabirzyanov N.A.
Properties of diffusion-hardening composite solder modified with tungsten powders – page 707
Abstract: The article considers the regulation of the properties of diffusion-hardening solder based on a low-melting gallium-tin-zinc alloy and copper-tin alloy powder by introducing inert tungsten metal powders. After heat treatment at low temperatures (125°C), the microhardness of composite diffusion-hardening solders with a tungsten content of 5, 10, 15 and 20% is estimated. It is shown that the heat treatment at low temperatures for 6 hours does not lead the solder to reach an equilibrium state, physico-chemical transformations are still ongoing, which shows an increase in the hardness of the samples after two months. The X–ray phase analysis has been used to determine the phases formed as a result of the diffusion hardening: micro- and nanoscale intermetallic compounds and metallic tin in the form of nanoscale inclusions in the space between the grains of copper alloy powder. Due to small additions of tungsten as a filler, inert to the effects of gallium, but well wetted by it, the characteristics of diffusion-hardening solder are improved. Judging by the microhardness, the introduction of 15% tungsten is optimal.
Keywords: composite diffusion-hardening solders, metal powder, properties, tungsten, microhardness, differential thermal analysis.

Sokolova E.M., Boiko A.S., Fokina M.I., Ponomareva A.A.
Development of tetraethoxysilane-based polymer absorbing coating with an adding of the cobalt oxide for a laser surgery – page 717
Abstract: The use of generated jets as «micro incisors» finds its application in laser surgery. Such methods of laser exposure are used to remove neoplasms, such as intervertebral hernias and cysts. An optical fiber is attached to the laser, which is inserted into the hernia or cyst through a puncture needle. To increase the efficiency of laser exposure, it is necessary to accumulate energy at the end of the waveguide by forming an absorbing coating, which should have high adhesion to quartz. In this work, a study was carried out on the development of a technique for polymer films by the sol-gel method for use in laser surgery as an absorbing coating. Tetraethoxysilane was chosen as a precursor for the formation of a polysilicate mesh holding small cobalt oxide particles. Optical, morphological, and absorbing properties of coatings obtained onto quartz glasses were studied in this work. Additionally, the solutions and the obtained coatings were studied using IR spectroscopy, the results of which showed the absence of a qualitative change in the sols during long-term storage (up to 3 weeks) and the formation of a three-dimensional silicate network and cobalt oxide in the films. The study of the surface morphology of the obtained coatings showed that high concentrations of cobalt salts are not required for the uniform distribution of the synthesized cobalt oxide. The absorbing properties of the samples were tested using an IR laser and a thermal imager. Owing to the research the optimal composition of the coating for the deposition on quartz waveguides was chosen.
Keywords: tetraethoxysilane, cobalt oxide, quartz, sol-gel technology, IR spectroscopy, laser radiation, absorbing coating.

Shomakhov Z.V., Nalimova S.S., Shurdumov B.Z., Maximov A.I., Moshnikov V.A.
Zinc stannate nanostructures for fast response gas sensors – page 726
Abstract: The possibilities of using zinc stannate nanostructures as sensitive elements of fast response gas sensors are considered, which are of great interest for use in a variety of applications from the detection of toxic substances to air quality monitoring or medical diagnostics. The synthesis of zinc stannate nanostructures was carried out by hydrothermal treatment of zinc stannate nanorods in a solution of potassium stannate and urea at different concentrations of precursors. The chemical composition of the sample surface was analyzed by X-ray photoelectron spectroscopy. It is shown that as a result of hydrothermal treatment, Sn4+ ions appear on the surface of zinc oxide nanorods. The study of gas-sensitive characteristics was carried out under the influence of isopropyl alcohol vapors at temperatures of 156°C and 310°C. It is shown that the maximum response at 310°C to 1000 ppm of isopropyl alcohol is 8,24. At the same time, the zinc stannate samples have a fast response of 23 s.
Keywords: .

Yurov V.M., Ibragimova D.A., Portnov V.S., Mausymbayeva A.D.
Nanostructures of rare-earth metals in the coals of the shubarkol deposit – page 736
Abstract: The rare metals of the Shubarkol coal deposit have a surface layer thickness of about 3 nm, i.e. are nanostructures. The thickness of the surface layer of the coal itself is of about 0,2 µm, i.e. it is a mesostructure. The pore radius in the coal substance is 30,6 nm, which corresponds to mesopores, and the specific surface area of coal is 857 m2/g. Rare metals, either in the form of pure impurities (~ 3 nm), or in the form of oxides (~ 7 nm), or in the form of organic impurities (~ 1-3 nm), freely enter into mesopores of the coal. The forms of occurrence of uranium and rare metals in the coals of the Shubarkol deposit indicate that their concentration in the coal is due to the leading role of the hydrogenous mechanism. In the d(I) layer, all rare metals are nanoluminophores, which can be considered as sensitive molecular probes for studying the structure of coal. It is emphasized that the influence of size effects on kinetics of the luminescence decay and anomalous thermalization of rare earths can be easily obtained experimentally. The fractal dimension of Shubarkol coal is 2,60, which is lower than that of anthracite – 2,74. In the mesoporous structure of Shubarkol coal, the adsorption of rare metal impurities is highly developed due to the formation of adsorption layers on the surface of these mesopores, which lead to volumetric filling of these pores by mechanism of the capillary condensation.
Keywords: surface layer, rare metal, nanostructure, mesostructure, atomic volume, size effect, carbon matter, fractal.

5. NANOCHEMISTRY – page 747

Bibanaeva S.A.
Synthesis of aluminosilicate zeolites in the conditions of alumina production – page 747
Abstract: The work is devoted to study of the possibility of obtaining synthetic sodium and calcium aluminosilicates from recycled solutions of alumina production by the hydro-alkaline method. The chemical qualitative and quantitative composition and morphology of zeolites obtained under conditions of high-temperature autoclave leaching have been studied. X-ray phase studies aimed at determining the composition and structure of the obtained aluminosilicate zeolites were carried out. The prospects of the method of the autoclave synthesis of synthetic zeolites with a high yield of the final product with the particle size up to 5 microns are shown. It has been established that the method allows the production of zeolites in parallel with the technological scheme of bauxite processing at an alumina plant, while minimally weighing down the production process. The resulting aluminosilicate zeolite has a wide range of applications in various industries. According to the results of the research, 2 applications for invention patents were filed.
Keywords: circulating solution, zeolite, calcium aluminosilicate, processing, calcium oxide, alumina production.

Blinov A.V., Slyadneva K.S., Gvozdenko A.A., Golik A.B., Taravanov M.A., Nazaretova E.D.
The effect of the mixing rate of the reaction mixture on the dispersed characteristics of the nanoemulsion of fat-soluble vitamin E (alpha-tocopherol acetate) – page 754
Abstract: The article presents the results of a study of the effect of the mixing rate on the dispersed characteristics of nanoemulsions of the fat-soluble vitamin E (alpha-tocopherol acetate). The mixing speed was varied in the range of 3000-22500 rpm. The average hydrodynamic radius of the micelles of fat-soluble vitamin E was considered as an output parameter, which was determined by the method of the dynamic light scattering. It was found that as a result of synthesis, micelles of the fat-soluble vitamin E emulsions are formed, having a monomodal size distribution. The smallest average hydrodynamic radius of the particles was 22 nm. It was found that an increase in the mixing speed from 3000 to 22500 rpm causes a decrease in the average hydrodynamic radius of micelles. The greatest changes are observed at τ = 30 s: a decrease in the average hydrodynamic radius of micelles Rm occurs by 3,3 times (from 210 to 63 nm). It is important to note that an increase in other synthesis parameters also leads to a decrease in the value of the average hydrodynamic radius of micelles of the vitamin E nanoemulsions. By v = 22500 rpm an increase in the mixing time τ from 30 s to 270 s leads to a decrease in Rm by 19 nm (from 63 to 44 nm).
Keywords: fat-soluble vitamin E, nanoemulsion, hydrodynamic radius, mixing speed.

Blinova A.A., Yasnaya M.A., Maglakelidze D.G., Taravanov M.A., Lapin V.A., Leontiev P.S.
Study of the structure and properties of zinc silicate stabilized with L-histidine – page 763
Abstract: This paper presents the results of a study of the process of stabilization of zinc silicate nanoparticles using the amino acid L-histidine. Zinc acetate was used as a precursor, sodium silicate was used as a precipitant, and the amino acid L -histidine acted as a stabilizer. Synthesis was carried out by chemical precipitation in an aqueous medium. A simultaneous thermal analysis was carried out, as a result of which it was found that the addition of an amino acid to nanosized zinc silicate has a great influence on the crystal structure and thermal transitions for this material. Next, the X-ray phase analysis was carried out, which showed that of zinc silicate particles have an amorphous structure and are in a nanoscale state. At the next stage of the work, the process of interaction of an amino acid with a zinc silicate particle was studied by IR spectroscopy. The results of the study showed that stabilization of particles is accompanied by the formation of a chemical bond between silicon in the zinc silicate molecule and the amino group in the L -histidine molecule.
Keywords: nanosized zinc silicate, amino acids, L-histidine, zinc acetate, sodium silicate, phase composition, simultaneous thermal analysis, derivatogram, IR spectroscopy, powder diffractometry.

Bogdanova E.A., Skachkov V.M., Nefedova K.V.
Development of composite mixtures based on hydroxyapatite and biogenic elements for the formation of bioactive coatings – page 771
Abstract: The hardened composite material with a porous structure was obtained by mechanochemical synthesis of nanostructured hydroxyapatite synthesized by precipitation from an aqueous solution with reinforcing additives of zirconium dioxide and silicic acid. Food gelatin is used as a binder. The influence of the phase composition on the physico-chemical properties of coatings (adhesive strength, microhardness, specific surface area, microstructure) is estimated. It has been established that the use of composite material together with gelatin as a part of a bioactive coating makes it possible to increase its hardness and adhesive strength. A patent application has been filed for the developed bioactive coatings based on nanoscale hydroxyapatite and biogenic elements with a binding agent. The composition of the dry mixture based on hydroxyapatite has been developed, which ensures a long shelf life without negative consequences and creates simple transportation conditions. Dilution of the dry mixture with distilled water gives a suspension that is convenient to use for coating implants of any configuration.
Keywords: hydroxyapatite, composite materials, biogenic elements, gelatin, collagen, bioactive coatings, adhesion.

Krut’ko V.K., Doroshenko A.E., Musskaya O.N., Kulak A.I.
Obtaining octacalium phosphate in aqueous medium during the interaction of calcite with monocalcium phosphate monohydrate – page 782
Abstract: Calcium phosphate composite powders consisting of brushite and calcite were obtained in an aqueous medium from a CaCO3/Ca(H2PO4)2 suspension at Ca/P ratios of 1,33, 1,50, 1,67, pH 5–7, and maturation time of 21-50 days. Prolonged maturation (up to 68 days) of composite calcium phosphate powders led to a hydrolytic transition of brushite to octacalcium phosphate, the amount of which increased with increasing duration of the maturation stage. Drying calcium phosphate powders at 37°C for 24 h contributed to the partially transition of the metastable phase of octacalcium phosphate to apatite represented by amorphous calcium phosphate. The presence of vibrations of О–Н at 633 cm-1 as the shoulder on the IR spectra indicates the presence of apatite in calcium phosphate powders. The use of an electric current (20 mA/cm2, 3–20 min) for a local increase of the pH value made it possible to increase the amount of octacalcium phosphate in the composition of the composite powder, which has a characteristic rosette morphology of thin lamellar crystallites.
Keywords: octacalcium phosphate, calcite, monocalcium phosphate monohydrate, brushite, apatite, hydrolytic maturation.

Krut’ko V.K., Maslova L.Yu.., Musskaya O.N., Kulak A.I.
Composites based on calcium phosphate foam ceramic and hydroxyapatite gel – page 791
Abstract: Bioactive calcium phosphate composites were obtained, consisting of open-pore multiphase calcium phosphate foam ceramic based on α / β-tricalcium phosphate, β-calcium pyrophosphate, biomimetic apatite and 5% hydroxyapatite gel at a mass ratio (ceramic foam / hydroxyapatite gel) of 1:3 and 1:10. Preliminary modification of the calcium phosphate foam ceramic with biomimetic apatite in a concentrated SBF×5 solution allows increasing the static strength to 0,05 MPa with a slight decrease in porosity and maintaining the open-pore structure of polyurethane foam. Calcium phosphate composites have increased resorbability in SBF×5 and are resorbed 3–5 times faster compared to calcium phosphate foam ceramic. The presence of a significant amount of hydroxyapatite gel increases the rate of resorption of calcium phosphate foam ceramic and the ongoing processes of apatite formation with the participation of SBF×5 ions due to its high reactivity. The obtained calcium phosphate composites are used in regenerative treatments to fill bone defects in unloaded areas.
Keywords: calcium phosphate foam ceramic, tricalcium phosphate, hydroxyapatite gel, simulated body fluid, biomimetic apatite, resorbability.

Medyankina I.S., Svetlakova K.I., Pasechnik L.A.
Formation of cobalt hydroxosilicate in amorphous silica matrix – page 800
Abstract: The synthesis of cobalt hydroxysilicate Co3(Si2O5)2(OH)2 in a matrix of high dispersity amorphous silica has been proposed. It is shown the formation of a hydroxosilicate, which combines coordinated silica and cobalt-oxygen polyhedrons in the overall structure, as well as the availability of surface hydroxyl groups, contribute to the preservation of a high specific surface area as is in amorphous SiO2. The hydroxosilicate also contributes to the effective manifestation of photocatalytic properties due to the presence of cobalt (2+), which has a high reactivity. As methods of synthesis of SiO2/Сo composites hydrochemical methods are used by impregnation and autoclave treatment with solution of cobalt formate of silica. The influence of the amount of introduced cobalt on the composition, structure, and properties of a composite material containing Co3(Si2O5)2(OH)2 in a SiOmatrix has been traced. SiO2/Co composites have been tested in the hydroquinone photooxidation reaction when exposed to ultraviolet radiation. The highest degree of hydroquinone decomposition amounting to 84% in 18 hours was achieved for SiO2/Co at a molar ratio of components Co:Si = 0.01:1.
Keywords: amorphous silica, cobalt silicate, hydrothermal synthesis, mechanosynthesis, microstructure, photocatalysis, hydroquinone.

Musskaya O.N., Krut’ko V.K., Kulak A.I., Krutsko E.N.
Modification of fiber cellulose materials with amorphized calcium phosphates and copper nanoparticles – page 811
Abstract: Etherification of the surface of cellulose carriers with phosphoric acid in the presence of urea yielded fiber materials characterized by an increased degree of swelling in aqueous media (by a factor of 1,1-1,5). The copper nanoparticles and their composites with amorphized calcium phosphates were synthesized by the borohydride method using the sodium salt of carboxymethyl cellulose as a stabilizer polymer. The obtained colloidal solutions of copper and their composites with hydroxyapatite are characterized by stability from several days to 2 months. It was found that the modification of cellulose materials (initial and phosphorylated) by the immersion method using aqueous compositions containing amorphized calcium phosphates, copper nanoparticles or composites based on them in the presence of sodium carboxymethylcellulose and ascorbic acid at pH 6 and 11 leads to a decrease in the crystallinity of the polymer carrier. It has been shown by IR spectroscopy that the amorphization of modified fiber cellulose materials is due to a change in the static homogeneity of the system of hydrogen bonds in the polymer structure.
Keywords: cellulose, phosphorylated cellulose, sodium carboxymethylcellulose, amorphized calcium phosphates, hydroxyapatite, copper nanoparticles.

Ostroushko A.A., Zhulanova (Maksimchuk) T.Yu., Kudyukov E.V., Gagarin I.D., Russkikh O.V.
Lanthanum manganite nanopowders synthesis via combustion reactions under the influence of electromagnetic field – page 820
Abstract: Lanthanum manganite doped with strontium samples were synthesized by the combustion method of nitrate-organic precursors of different composition. The combustion process was realized under the influence of an external alternating electromagnetic field and in its absence. It was found that thermochemical generation of charges occurs during precursor’s combustion, recorded as a potential difference of precursor-earth. It is shown that the composition of the initial precursor (organic component and its quantity), as well as the presence of an external alternating electromagnetic field, affect the magnitude of the potential difference that occurs, varying from -7 to 125 V. The relationship between the studied electromagnetic properties (saturation magnetization, coercive force, Curie temperature) of the obtained samples and the precursor–earth potential difference arising during synthesis is shown. The Curie temperature values varied in the range of 38-79°C for samples obtained under the influence of an alternating electro-magnetic field, and 49-104°C in its absence.
Keywords: Complex oxides, lanthanum manganite, synthesis, combustion reactions, charges, electromagnetic field, magnetic properties.

Ostroushko A.A., Menshikov S.Yu.., Rozhentsev D.A., Tkachev N.K., Golub A.Ya.., Tonkushina M.O.
Nanostructured catalysts of the turpentine emulsion polymerization under the influence of potassium persulphate – page 829
Abstract: We have revealed the catalytic activity for initiating the water-emulsion turpentine polymerization of some nanostructured materials such as Keplerate type Mo72Fe30 nanocluster polyoxometalate, nanoporous iron and nanoporous composite of intermetallic compounds Pd2In@Pd3In obtained by dealloying of equiatomic alloys Fe – Mn and Pd – In. For polyoxometalate solutions and nanoporous metal samples, respectively, the yield of sufficiently pure polyterpene resins when using the potassium persulphate initiation depends on the nature of the contact between the catalysts and substrates: solid-liquid-liquid or liquid-liquid. A system that did not contain catalysts was taken as the reaction medium for comparison. Based on the obtained data on the softening point, the molecular weight of the resin samples was determined. Infrared spectroscopy was used to identify the obtained products. In the reaction medium (mainly aqueous) after the isolation of polyterpene resins, chromatographic analysis revealed so valuable products as alpha-terpineol, which is used as an intermediate for obtaining flavors and flotation agents.
Keywords: Nanostructured initiation catalysts, polyoxometalates, metals, emulsion polymerization, turpentine, polyterpene resins, potassium persulfate.

Permiakov N.V., Lebedeva A.I., Maraeva E.V.
Obtainanig and study of the material based on hydroxyapatite and polycaprolactone for extrusion three- dimensional printing – page 838
Abstract: The work is devoted to the search for a scientific and technical solution for the creation of filaments based on hydroxyapatite and polycaprolactone for extrusion three-dimensional printing. Hydroxyapatite powders were obtained by chemical precipitation using microwave radiation, and the average particle size in the powder was determined. Options for creating a filament by extrusion based on a composition of hydroxyapatite and polycaproloctone for subsequent printing of scaffolds (temporary scaffolds necessary for the formation of new functional tissues) are proposed. Images of the surface of calcium hydroxyapatite were obtained using a scanning probe microscope to assess the parameters of surface roughness, which is one of the most important factors for successful cell adhesion to the scaffold surface during osseointegration processes.
Keywords: hydroxyapatite, polycaprolactone, 3D printing, nanocomposite, scaffold, scanning probe microscopy.