Abstracts archive – Issue 10 (2018)
Aleroev M.A., Ashkhotov O.G., Ashkhotova I.B.
Kinetics of electronic spectra of surface of india with adsorbed oxygen – page 6
Abstract: The spectra of Auger and plasmon losses of polycrystalline indium before and after aging in an oxygen medium have been studied. The kinetics of electronic states on the surface of indium with adsorbed layers of oxygen (exposure in an oxygen medium up to 5000 Langmuir and at atmospheric pressure at room temperature) is studied. It is shown that aging in an oxygen medium leads to the formation of an ordered oxide layer consisting of In2O3+In+O.
Keywords: surface, adsorption, indium, oxide, energy, spectroscopy, oxygen, analysis, ion, bond, atom.
Antonova E.S., Pastushenkov Yu.G.
Features of the low-temperature transformation in the micromagnetic structure of the intermetallic compound Ho2Fe17 – page 13
Abstract: We found that a three-phase micromagnetic structure may emerge when a magnetic field is applied to the intermetallic compound Ho2Fe17 with the magnetic crystallographic anisotropy of the «easy plane» type in the temperature range 10 ÷ 110 К. Using the method of magneto-optic Kerr effect, the temperature dependence of the field value where the third magnetic phase emerges was determined.
Keywords: micromagnetic structure, magnetic anisotropy of the type «easy plane», rare-earth intermetallic compounds, three-phase magnetic structure.
Apekov A.M., Shebzukhova I.G.
Polarization and dispersion corrections to the interfacial energy of the facets at the boundary between calcium/barium crystals and nonpolar organic liquids – page 20
Abstract: In this paper we have obtained polarization and dispersion corrections to the interfacial energy of the faces at the boundary between calcium and barium crystals of low-temperature modifications and nonpolar organic liquids using the electron-statistical method. We have shown orientation dependence of the corrections and interfacial energy of the crystals in view of polarization and dispersion corrections.
Keywords: interfacial energy, polarization correction, dispersion correction, electron-statistical method, nonpolar organic liquid, barium, calcium.
Aref`eva L.P., Shebzukhova I.G.
Wetting and anisotropy of interfacial energy on the contact boundary of indium nanocryctals and orientied substrate – page 27
Abstract: We propose a technique for estimating the wetting and anisotropy of the interfacial energy at the interface between the metal particles (indium) with a substrate based on the construction of the Winterbottom equilibrium shape of the crystal. The effective contact angle and the ratio of interfacial energies at the particle-substrate interface are calculated from the experimental data of the geometric characteristics of the particles obtained by analyzing the AFM images of the samples. The obtained dependences are qualitatively consistent with thermodynamic states and known data for other systems.
Keywords: interface energy, wetting, nanocrystals, indium, Winterbottom analysis, atomic-force microscopic.
Aref`eva L.P., Shebzukhova I.G.
The interfacial energy of metalic thin films on the boundary with liquid polar dielectric – page 35
Abstract: Expressions have been obtained for estimating the interfacial energy of metallic thin films at the interface with an organic dielectric coating. The case of the boundary of the contact of cobalt films with polyatomic alcohols (diols) is considered. Comparison with the experimental data shows a good agreement between the theoretical model and real objects.
Keyword: interface energy, polyatomic alcohols, thin films, polar organic dielectric.
Ataeva A.Yu., Sverdlik G.I., Kambolov D.A., Ataev A.R.
Modern methods of granulometric analysis of dusted materials containing nanoparticles – page 44
Abstract: In the work the differential and integral distribution of particles of dolomite flour and wings of zinc-containing welsh furnaces by size was studied by the method of analytical disk centrifugation with X-ray detection. The results of measurements for large particles in the regime of natural sedimentation G and for small particles, including nanoparticles, are considered in the centrifugation regime X.
Keywords: granulometric analysis, sedimentation regime, centrifugation mode, basis of weighing, nanoparticles, detection principle.
Akhmedov E.N.
Gold nanocrystal properties dependence on size and shape at isobaric conditions – page 53
Abstract: Using the nanocrystal RP-model, the state equation of a gold was calculated. On the basis of this equation the isobaric dependence of the melting temperature on the size and shape was obtained at P = 0. It is shown, that the stronger the shape of the nanocrystal deviates from the most energetically effective one, the bigger the size of the nanocrystal at the crystallization start point. Approximation of such points for various shapes made it possible to determine the crystallization start temperature of the Au macrocrystal: Tcr(N = ∞, P = 0) = 921K, which coincided with the rule of Turnbull.
Keywords: equation of state, nanocrystal, gold, size, shape.
Baidyshev V.S.
Computer simulation of the Cu@Si core-shell nanoparticles formation – page 64
Abstract: In this work computer simulation of the condensation processes of Cu-Si core-shell nanoparticles was performed by the molecular dynamics method. It was shown that simultaneous cooling of atomic vapors of copper and silicon leads to the formation of disordered CuSi alloy particles. A possible mechanism for the formation of nanoparticles (Cu – core, Si – shell) is associated with deposition of small silicon clusters onto a pre-formed copper core.
Keywords: computer simulation, molecular dynamics, core-shell nanoparticles, condensation.
Barakhtin B.K., Sedletsky R.V.
Peculiarities of structural variations at crystallization of highly filled composites on polymeric basis – page 73
Abstract: Composite samples with polymer matrixes of different compositions are investigated. The volume fraction carbon fillings of globular form quasi-isotropically distributed in the samples was found to range from 0.4 to 0.7. Under increasing the density, the modulus of elasticity and strength of the composites under discussion, some the quasi-periodical oscillations of mechanical parameters are discovered accompanied by changing both the value and sign of the Poisson coefficient. The nature of this phenomena has been established and a model of the structural variations has been proposed.
Keywords: polymer composite materials, mechanical tests, Poisson coefficient.
Bembel A.G., Talyzin I.V., Samsonov V.M.
Solid state wetting and dynamics of solid surface nanorelief – page 83
Abstract: Using molecular dynamics solid state wetting in the Cu (nanoparticle) / Cu (substrate) system was studied. It has been found that the solid state spreading mechanism corresponds, first of all, to the surface diffusion that was confirmed by the linear dependence of square radii of the first monolayer on the spreading time. A hypophysis was put forward and justified that the degradation of nanorelief of the solid surface occurs by means of the solid state wetting mechanism.
Keywords: solid state wetting, surface diffusion, nanoparticle, surface, nanorelief, molecular dynamics.
Bernatskii D.P., Pavlov V.G.
The effect of carbon on the diffusion of cesium on the renium surface – page 93
Abstract: The diffusion of cesium over the rhenium surface and the rhenium surface coated with carbon was studied by methods of the field electron and desorption microscopy. The method of continuous field desorption was used, in which surface diffusion ensures the flow of the adsorbate to the desorption site. It was found that the carbon-coated surface undergoes intensive diffusion of cesium, while there is no diffusion on the rhenium surface.
Keywords: surface diffusion, alkali metals, electric field, carbon, rhenium.
Bernatskii D.P., Pavlov V.G.
Application of the method of field desorption of sodium for studying carbon nanostructures on the surface of rhenium field emitter – page 99
Abstract: Field desorption microscopy was used to study the surface of the rhenium field emitter after its carbonization. Field electron and field desorption images of the surface after carbonation at adsorption of sodium atoms are obtained. On the basis on the analysis of modifications of the field electron and field desorption images of the surface at different values of the electric field we concluded that formation on the surface of the carbonized rhenium of bulk graphite nanostructures affects the emission processes.
Keywords: field desorption microscopy, electric field, field emitter, alkali metals, carbon nanostructures.
Berov Z.Zh., Manukyants A.R., Kasumov Y.N., Sozaev V.A.
Fhase forming and structural feature twu-layer coating «titanium/nichrome» on artificial polycrystalline diamonds – page 106
Abstract: The phase forming and the structural features of two-layer coating «titan/nichrome» on the surface of artificial polycrystalline diamonds ASB-4 are examined. The film was deposited by method of ion-plasma vacuum 10-2 Pа evaporation. The X-ray-phase film analysis indicated that at the surface the phases Ni4Ti3, Cr7Ni3, Cr2Ti, Cr0,875Ti0,125, NiTi and others are organized. In the films it is seen the fomation of spherical phases, conceivably Cr0,075Ti0,125. On diamond films, obtained by recuperation, the structural patterns are seen which are typical for Zn.
Keywords: phase forming, ion-plasma metallization, recuperation, diamonds.
Blinov A.V., Snezhkova Yu.Yu., Yasnaya M.A., Dyudyun O.A., Kaznacheev Y.V., Shevchenko I.M.
Comparison of the ζ-potential measuring methods accuracy for the colloidal particles – page 115
Abstract: The study is devoted to the choice of an optimal method for determining the ζ-potential of colloidal SiO2 particles. The electrokinetic potential was measured using two methods: (i) acoustic and electro-acoustic spectroscopy; (ii) horizontal agarose gel electrophoresis. Based on experimental and calculated data, an optimal method for measuring the ζ-potential of colloidal SiO2 particles was chosen.
Keywords: ζ-potential, electro-acoustic spectroscopy, electrophoresis, absolute error, relative and normalized error, distribution of the mean square deviation.
Bobreva L.A., Masloboeva S.M., Sidorov N.V., Palatnikov M.N.
Obtaining and investigation of the structural features of the LiNbO3:Zn (2,12 wt. % Zn) single crystal – page 124
Abstract. We carried out preparation of homogeneously doped charge LiNbO3:Zn ([Zn] = 2,44 wt. %) of congruent composition (ratio [Li]/[Nb]=0,96). From this charge a LiNbO3:Zn (Zn ~ 2.12 wt. %) single crystal by the Czochralski method was grown. Defect complexes (VLi)—-OH— of the LiNbO3 cong and LiNbO3:Zn crystals were discovered by IR-absorption spectroscopy in the area of stretching vibrations of OH—-groups.
Keywords: homogeneous doping, charge, single crystal, lithium niobate, stretching vibrations of OH——groups.
Bogdanova E.A., Skachkov V.M., Shirokova A.G., Sabirzyanov N.A.
The use of different forms of hydroxyapatite to create a bioactive coating on a porous titanium-base – page 133
Abstract: The article discusses methods of creating a bioactive composite on a porous titanium base. The possibility of formation of coatings based on colloidal hydroxyapatite and an aqueous suspension of powder hydroxyapatite in various ways has been studied. The adhesive properties of the obtained coatings are estimated.
Keywords: biocomposites, functional bioactive coating, strength properties, hydroxyapatite, porous titanium.
Bogdanova E.A., Skachkov V.M., Sabirzyanov N.A.
Study of the influence of anionic substitution in hydroxyapatite structure and properties of ceramics on it based – page 142
Abstract: The article discusses the possibility of strengthening stoichiometric hydroxyapatite obtained by precipitation from the solution by partial substitution of phosphate groups with silicate ions. Such characteristics of samples as phase composition, morphology, particle size distribution, specific surface area have been studied. It was established that the degree of substitution affects the mechanical properties of synthesized powders and ceramics after annealing.
Keywords: hydroxyapatite, silicon-substituted hydroxyapatite, biocomposites, microhardness.
Bolotov A.N., Novikov V.V., Novikova O.O.
Hard lubricant ceramic coatings with nano- and microdispersed filler – page 150
Abstract: A basis was developed for a technology of the solid lubricant ceramic coatings with antifriction filler. We have made physical, mechanical and tribotechnical tests of the received materials and gave a recommendation for their practical application.
Keywords: composite ceramic coatings, hard lubricant materials, antifriction fillers, nanodispersed particles, friction, wear.
Bolotov A.N., Novikov V.V., Novikova O.O.
Lubricating oils on the basis of nanoliquids – page 159
Abstract: We established applicability of dispersed medium based on diesters of carbonic acids for production the low-viscosity magnetic oil of new generation. It was shown unusual approach to select surfactant-stabilizer for colloidal structure of oils considering their dielectric properties and friction effects. It was submitted the preselection findings of the additions and fillers for magnetic oil which are characterized by the different mechanism of reducing friction.
Keywords: magnetic lubricating oil, friction, wear, lubricant, dispersed medium, dispersed phase, antifriction and wearproof additives.
Bolshakova N.N., Bolshakova О.V., Ivanov V.V., Ivanova T.I., Semenova E.M.
Niobium-containing barium titanate crystals switching processes – page 169
Abstract: The results of research of the processes of polarization of niobium-containing crystals of barium titanate in changing electric fields are presented. It has been established that the time for reorganization of the ferroelastic domain structure is 30-40 times shorter than the switching time of the total polarization of the crystal, which indicates that the main switching time of BaTiO3 : Nb5+ crystals is determined by the change in its ferroelectric 180° domain structure.
Keywords: processes of switching, domain structure, barium titanate, polarization-optical method, Barkhausen effect.
Brylkin Yu.V., Zalogin G.N., Kusov A.L., Rudin N.F.
The error in probe measurements of heat flux dissociated gas streams – page 178
Abstract: The main error in strongly dissociated laminar gas jets (nitrogen, air, CO2) affecting the measured heat flux is the surface catalytic activity of the heat-receiving element with respect to the reactions of the heterogeneous recombination of atoms. The purpose of this work is to estimate the heat flux measurement errors due to the influence of the surface layer area on the micro-and nanoscale.
Keywords: catalytic activity, surface structure, heat flux.
Burtsev A.A., Butkovsky O.Ya.
Modeling fractal crystals forming on the surface of stainless steel by cellular automata – page 187
Abstract: In this paper experiments on crystallization from melts and results of analysis of the morphology of formed crystal structures are discussed. Some examples of forming complex dendritic formations are shown. Different types of the crystal morphology arise in dependence on the duration of heating and the energy of the acting radiation. Models of the distribution of crystallization centers and the growth of an individual cluster under the diffusion process were modelled by the methods of cellular automata. The relationship between the morphology and the model parameters is analyzed.
Keywords: laser heating, metal surface modification, crystallization, fractal, dendritic crystals, diffusion-limited aggregation, cellular automata.
Vazirov R.A., Sokovnin S.Yu., Ilves V.G.
Antioxidant properties of cerium dioxide nanoparticles – page 196
Abstract: Studies of biological activity of cerium dioxide nanoparticles show that this compound exhibits antioxidant, antitumor, antibacterial and antiviral properties. The cerium dioxide nanoparticles were obtained by evaporation of a target by a pulsed electron beam in a low-pressure gas with a specific surface area of 190 m2/g. To determine the enzyme-like activity of cerium dioxide nanoparticles, chemical analysis of interaction with the hydrogen peroxide was carried out. The results show an active inhibition of reactive oxygen species at pH above 6.
Keywords: nanopowder, nanoparticles, suspension, cerium dioxide, reactive oxygen species, antioxidant.
Vasilyev S.A., Kartoshkin A.Yu., Samsonov M.V., Dyakova E.V.
Melting of metal nanowires: molecular dynamics simulation – page 204
Abstract: A comparative molecular dynamics study has been carried out of the melting of infinite metallic nanowires and free spherical metallic nanoparticles of the same diameter. It was found that the nanowire is melted at a higher temperature than its spherical analogue as the shape of the nanowire is non-equilibrium. As a result, the melting of the nanowire leads to the loss of its stability, i.e. to the break of the nanowire.
Keywords: metal nanowire, melting, size dependence, molecular dynamics, free nanoparticle.
Gafner Yu.Ya., Gafner S.L., Redel L.V.
Nanostructures as a material for phase-inverse memory – page 210
Abstract: Despite on long researches, chalcogenide alloys are still generally used in the contemporary PCM layouts as the operating layer material undergoing structural transformations. However, the evolution of the technique aimed at the creation of new non-volatile arrays of information requires different technical solutions. First of all, it deals with the reduction of one bit storage area to several nanometers and reduction of the access time, in particular the possible application in the PCM memory of small metallic nanoclusters.
Keywords: phase transition, memory cells, nanostructures.
Gafner Yu.Ya., Bashkova D.A., Gafner S.L., Redel L.V.
Evaluation of applicability of small silver nanoparticles as the cells of PCM memory – page 219
Abstract: In this paper, one of the aspects of using metallic nanoclusters was considered, namely the use of silver nanoparticles as separate bits of information in memory devices based on the phase-change memory (PCM) method. The basic principle of this approach is that to locally change the phase state of a memory cell from crystalline to amorphous, keep this phase as long as you like and, if necessary, and return the material to its original crystalline state. Based on the results of simulation of silver nanostructures, it was concluded that their use as a memory element based on phase transitions is allowed, but with a particle size limitation exceeding 8.0 nm.
Keywords: phase transition, memory cells, silver, nanoclusters.
Gafner Yu.Ya., Bashkova D.A., Gafner S.L.
Using nanoparticles of Ag – Cu alloy as separate bits of PCM memory – page 226
Abstract: One of the promising areas of application of metallic nanoparticles is the creation of devices on their basis with a high information recording density that generates interest in the study of their magnetic, optical and structural-phase properties. In this paper, one of the aspects of using metallic nanoclusters. Namely we mean the use of silver-copper nanoparticles as separate bits of information in memory devices based on the phase-change memory.
Keywords: phase transition, memory cells, silver, copper, nanoclusters.
Grebenyuk G.S., Lobanova E.Yu., Pronin I.I.
The influence of the intercalated silicon on the graphene electronic structure – page 234
Abstract: Intercalation of the graphene-cobalt system with silicon was investigated experimentally. The ab initio calculation of the electronic structure of a low-dimensional graphene-silicon-cobalt system was carried out using the density functional theory. The most advantageous positions of intercalated Si atoms are determined. It is shown that the introduction of silicon under graphene leads to a sharp decrease in the interaction of carbon atoms with the substrate.
Keywords: graphene, intercalation, cobalt silicides, DFT calculations, thin films, photoelectron spectroscopy.
Ershov P.M., Kolosov A.Yu., Myasnichenko V.S., Sokolov D.N., Khort A.A., Bogdanov S.S., Shimanskaya H.N., Sdobnyakov N.Yu.
Invetigation of size dependences of melting and crystallization temperatures and specific excess surface energy of nickel nanoparticles under melting / crystallization phase transition – page 242
Abstract: The Monte Carlo method was used to study size dependences of the melting and crystallization temperatures of nickel nanoparticles, their hysteresis area, and changes in the specific excess surface energy during the direct and reverse melting/crystallization phase transition. Simulation results for nickel nanoclusters indicate the presence of melting and crystallization temperature regions, which generally correlates well with simulation results for other metals. We employed simulation by using the embedded atom model and tight-binding Cleri-Rosato potential. Results of three series of computer experiments for the size dependences of the melting and crystallization temperatures made using the two interatomic potentials in the software package LAMMPS and our own softwares were found to be in good accordance between themselves.
Keywords: nickel nanoparticles, Monte-Carlo method, Gupta potential, size dependences, melting and crystallization temperatures, specific excess surface energy.
Efremov V.V., Shcherbina O.B., Radyush Yu.V., Palatnikov M.N.
Microstructure, phase states, dielectric and elastic properties of ceramic solid solutions Li0,17Na0,83NbyTa1-yO3 obtained at high pressure – page 252
Abstract: Microstructure and elastic properties of ferroelectric ceramic solid solutions Li0,17Na0,83NbyTa1-yO3 with a perovskite structure were investigated, obtained by thermobaric synthesis at high pressures and temperatures. The electrical characteristics and phase states of a series of ferroelectric high-pressure solid solutions Li0,17Na0,83NbyTa1-yO3 ( y = 0,1 — 0,5 ) were investigated by the impedance spectroscopy method. Some anomalies are revealed in ε'(T) and σsv(T) dependencies associated with phase transitions in the studied ceramic samples. The values were established of the static conductivity as a function of the temperature and enthalpy of activation of charge carriers. It was found that Li0,17Na0,83NbyTa1-yO3 is a high-temperature superionic.
Keywords: solid ferroelectric high-pressure solutions, microstructure, Young’s modulus, impedance spectroscopy, dielectric permittivity, electrical conductivity.
Zlygosteva O.A., Sokovnin S.Yu., Il’ves V.G.
The use of SiO2 — MnO2 nanopowders for targeted drug delivery – page 262
Abstract: Application of manganese-doped mesoporous silica nanopowders SiO2 — MnO2 for targeted drug delivery was researched. It has been established that an increase in sonicated time leads to changes in the NP structure. The produced nanopowders have a high loading capacity 0,09 mg of Amoxicillin per mg of nanopowder, 0,075 mg of Doxorubicin per mg of nanopowder that is five times higher than the loading capacity of chemically synthesized nanopowders.
Keywords: mesoporous silica nanopowder, dopant manganese dioxide, targeted drug delivery.
Ivanov V.V., Golubeva E.N., Sergeeva O.N., Nekrasova G.M., Pronin I.P., Kiselev D.A.
Peculiarities of the process of switching polarization in polycrystalline thin films of lead zirconate-titanate – page 270
Abstract: The paper presents the results of a study of relaxation of the dielectric permittivities in constant electric fields upon switching the polarization of thin films of lead zirconate-titanate, crystallized at different annealing temperatures. It is shown that the relaxation processes are characterized by at least three relaxation times which depend on the crystallization temperature. It is shown that the relaxation processes depend on the localization of lead oxide in the bulk of the film.
Keywords: thin films of lead zirconate-titanate, dielectric permeability, relaxation time, crystallization temperature, lead oxide.
Ivanov V.I., Ivanova G.D., Mjagotin A.V.
Thermodiffusion contribution in the thermal lens response of the nanosuspension – page 280
Abstract: A new two-beam configuration of the thermal lens method for the nonlinear optical diagnostics of nanosuspensions is presented. The proposed configuration eliminates the influence of the electrostrictive response and thus provides the determination of thermodiffusion coefficient of nanoparticles.
Keywords: thermal lens response, nanosuspension, thermodiffusion, electrostriction.
Ivanov V.I., Ivanova G.D., Krylov V.I., Khe V.K.
Sedimentation of nanoparticles under the action of light pressure forces in liquid media – page 286
Abstract: A model of sedimentation of nanoparticles in a uniform light field is considered as an alternative to methods of precipitation in a gravitational field and centrifugation. The exact analytical solution of the one-dimensional nonstationary mass transfer problem in a bounded cell is given. The main parameters of the centrifugal and light-induced sedimentations of nanoparticles are compared.
Keywords: sedimentation, dispersed media, light pressure.
Ivanov D.V., Antonov A.S., Sdobnyakov N.Yu., Shimanskaya H.N., Romanovskaia E.V., Afanasiev M.S.
About «technological» properties of nano-sized nickel and copper films – page 291
Abstract: As an example of studying morphology of the relief of nickel and copper nano-sized films on the mica surface, it is possible to create a technology to «grow» structures with a given surface morphology using a scanning tunneling microscope. The characteristic features of the film surface nanorelief are described, including fractal properties. The current-voltage characteristics of a metal-to-metal contact for nickel and copper films with a tungsten tip are obtained. It is shown that for surface areas containing fractal structures, the current-voltage characteristics may differ from the dependences obtained on ordinary surfaces.
Keywords: scanning tunneling microscopy, nanorelief, fractal dimension, nanoscale films of nickel and copper, current-voltage characteristic, tunnel contact.
Ivanov Yu.F., Denisova Yu.A., Petrikova E.A., Teresov A.D., Lykov S.V., Ivanova О.V., Klopotov A.A.
Combined method of diffusion saturation of steel by nitrogen – page 304
Abstract: The results obtained during the study of 20H13 steel subjected to a combined treatment including irradiation with a pulsed electron beam and nitriding in a plasma of a low-pressure gas discharge are presented. It is shown that nitriding of steel previously irradiated with an electron beam makes it possible to increase in 1,8 times the microhardness of the surface layer of 140 μm in thickness on the original sample and in 1,4 times on the sample after nitriding.
Keywords: intense pulsed electron beam, nitriding, gas discharge plasma, nanoparticles, phase composition, defective substructure, properties.
Izmailov V.V., Novoselova M.V.
On nanotopographic parameters of engineering surface and its profile – page 313
Abstract: Amplitude and spacing parameters of engineering surfaces nanotopography and some their correlations have been considered in comparison with similar parameters and correlations on a microscale level (microroughness). It is shown that on a nanoscale level theoretical and empirical relations characterizing a surface topography on a microscale level hold true.
Keywords: surface, topography, nanoroughness, microroughness, amplitude parameters, spacing parameters, correlations.
Ilves V.G., Sokovnin S.Yu., Zayats S.V., Murzakaev A.M., Demina Т.М., Zuev M.G.
Properties of compacts from BaF2 nano-powder obtained by pulsed electron beam evaporation – page 322
Abstract: In this work, a mesoporous crystalline BaF2 nanopowder with specific surface area (Sred) up to 34,8 m2/g was obtained by evaporation of targets of a micron BaF2 powder (Sred = 0,38 m2/g) of optical purity with a pulsed electron beam. Textural and thermal features of BaF2 nanopowder (before and after annealing at 200°C in air) and individual properties of compacts made from BaF2 nanopowder by pulsed magnetic pressing and static pressing are studied. By means of pulsed magnetic pressing in vacuum at a temperature of about 425°C, vitreous, opaque compacts of black color, promising for use as scintillators and dosimeters, were obtained. The effect of pressing methods on the cathodoluminescence and photoluminescence characteristics of compacts from BaF2 is studied.
Keywords: pulsed electron beam evaporation, nanocrystalline barium fluoride, textural and thermal properties of BaF2 nanopowder, luminescence of compacts from BaF2 nanopowder.
Kandaurov M.V., Vladimirova E.V., Dmitriev A.V.
Sol-gel fabrication, morphology and magnetic properties of multiferroics BiFe1-xMnxO3 – page 330
Astract: Experimental data on the synthesis and properties of the solid solution BiFe1-xMnxO3 are given. The length of the solid solution (0 ≤ x ≤ 0,20) was established, the morphology of the particles and magnetic properties of the samples were investigated in dependence on the content of a dopant. Nonlinear concentration dependences of magnetic characteristics for BiFe1-xMnxO3 with a maximum at the manganese 5 — 7 mol. %. content were found.
Keywords: bismuth ferrite, doping, sol-gel method, morphology, agglomerates, solid solution, phase composition, magnetic properties.
Karpenkov A.Yu., Dunaeva G.G., Rakunov P.A., Semenova E.M.
Method of analysis of the reversal magnetization processes using magnetic domain structure images – page 338
Abstract: A unique software and hardware system for obtaining and automatic analysis of the magnetic domain structure images in an external magnetic field for further study of the magnetization reversal process was developed. The method efficiency and possibility of its use for studying the magnetization reversal of local surface regions of magnetic materials are shown, using the experimental magnetization curves of an yttrium-iron garnet film.
Keywords: magnetic domains, magnetization reversal, magnetization curves, magnetic films, yttrium-iron garnet.
Kiseleva M.A., Sokovnin S.Yu., Balezin M.E.
Producing nanodimensional silver covering on aluminum oxide nanopowder – page 345
Abstract: The principal possibility of the composite particles production by the radiation-chemical method was shown. The composite particles were obtained in the nanoscale range ( 60 — 80 nm) from aluminum oxide partially coated with silver. The coating percentage was from 2 — 3% to 16 — 40%. The high efficiency of the production method was demonstrated. The ability to control the deposition process and the type of silver coating by changing the deposition time had also been established.
Keywords: radiation technology, nanoparticles, silver-coated alumina.
Knat’ko M.V., Lapushkin M.N.
Violation of the energy distribution of desorbiting ions Na+ in thermal ionization on the surface of NaAuy alloy – page 352
Abstract: The effect of the applied external electric field on the energy distribution of desorbed from the alloys are presented. It is shown that the energy distributions of the desorbed depend on the distribution of positive charge carriers near the surface that, in turn, depends on the external electric field.
Keywords: thermal ionization, adsorption, surface states, intermetallic alloys.
Kolosov A.Yu., Myasnichenko V.S., Bogdanov S.S., Romanovskiy V.I., Nepsha N.I., Shcherbatykh K.R., Sdobnyakov N.Yu.
On the regularities of formation of mono- and bimetallic nanoparticles in the coalescence process – page 359
Abstract: The simulation was carried out using two alternative Monte Carlo and molecular dynamics methods of the coalescence process with gradual thermal action for metallic nanoparticles based on nickel, aluminum, copper, silver and gold. The following types of mono- and bimetallic systems were considered: in the form of a sphere and in the form of two perpendicular blocks. It is established that the evolution of the coalescence process for monometallic nanoparticles differs significantly from that for bimetallic nanoparticles. Characteristics such as the coalescence temperature, the structure and shape of the neck, the dihedral angle between the nanoparticles can differ significantly. It is argued that it is impossible to accurately predict the behavior of a bimetallic system in the process of coalescence, knowing the evolution of the process of coalescence for monometallic systems consisting of the same metals.
Keywords: mono- and bimetallic nanoparticles, molecular dynamics, coalescence, Monte-Carlo method, molecular dynamics, dihedral angle.
Kotomkin A.V., Rusakova N.P., Turovtsev V.V., Orlov Yu.D.
Electronic integral characteristics of groups in the fluoro-substituted of isobutan and neopentan – page 368
Abstract: Within a «quantum theory of atoms in molecules» (QTAIM) the equilibrium geometry and the electron structure of fluoro-substituted molecules (CH3)2−CH−CH(3-n)Fn and (CH3)3−C−CH(3-n)Fn, where 1 ≤ n ≤ 3, were studied. Intramolecular interactions also discussed.
Keywords: branched fluorinealkanes, electronegativity, quantum theory of atoms in molecules, electron charge density, steric effect.
Krut’ko V.K., Kulak A.I., Musskaya O.N., Safronova T.V., Budeiko N.L.
Calcium phosphate foam ceramics with regulated bioactivity – page 374
Abstract: The introduction of a 10−50 mass.% of brushite powder or tricalcium phosphate heated at 50−70°C in a hydroxyapatite slip leads after annealing at 1200°C to formation of resorbable calcium phosphate phases which make it possible to regulate the degree of bioactivity of the foam ceramics.
Keywords: calcium phosphate foam ceramics, hydroxyapatite, brushite, tricalcium phosphate, bioactivity.
Kuznetsov Yu.A., Lavrovskaya N.P., Rut’kov E.V., Gall N.R.
Temperature effect on electron-stimulated desorption of cesium atoms from graphene on iridium – page 383
Abstract: Electron-stimulated desorption of cesium atoms from monolayer graphene on iridium has been observed at 160 K and 300 K. Migration processes have been shown to be frozen at 160 K, and cesium atoms to be located only at the graphene surface. At 300 K, due to intercalation an additional layer of cesium atoms is produced and located under the graphene layer. We believe that observed electron-stimulated desorption of cesium atoms is due to the non-metal nature of the adsorbed graphene film independently on the metal nature under it: iridium or cesium.
Keywords: electron-stimulated desorption, graphene, intercalation.
Kuznetsov Yu.A., Lapushkin M.N.
Electron-stimulated desorption of Cs atoms from graphene on Ir: experiment and model – page 393
Abstract: The processes of electron-stimulated desorption of Cs atoms from the graphene film on the iridium ribbon have been studied. The model of the Cs atom electron-stimulated desorption processes from the graphene film have been suggested. It has been shown the community and the difference of the electron-stimulated desorption processes for high-energy and low-energy peaks in the kinetic energy distributions of the desorbed atoms.
Keywords: electron-stimulated desorption, adsorption, alkali metals, graphene.
Kul’kov V.G., Syshchikov A.A.
Intergranular slippage on faceting boundaries with a bimodal distribution of facet dimensions – page 401
Abstract: The speed of mutual displacement of the grains along faceting boundary with two characteristic sizes of facets under the external shear stress is considered. Based on the solution of the stationary equation of diffusion of vacancies at the grain boundary, the distribution of their concentration and normal stresses along the facets is found. The presence of smaller facets leads to an increase in the speed of intergranular slippage.
Keywords: faceted grain boundaries, intergranular slippage, vacancies, diffusion.
Kumykov T.S., Nagaplezheva R.R.
The influence of the filler on the surface tension of a binary mixture of butadiene nitrile rubber (SKN-26) with polyvinyl chloride (PVC) – page 408
Abstract: The effect of the concentration of carbon black and aluminum oxide nano-additives on the surface tension of polymer-composite materials SCN-26 and PVC was investigated by the neutral drop method. Extreme changes in properties of the materials under study depending on the composition are found, which are explained by the effects of redistribution of high — and low-molecular fractions on the surface of the filler and colloidal chemical phenomena in the binary polymer mixture.
Keywords: neutral drop method, nanoparticle, filler, interphase phenomenon, polymer matrix.
Kurbanova E.D., Polukhin V.A.
Structure – dynamic effects in metal melts, glasses and nanocrystals in dependence of temperature – page 414
Abstract: The researchers have conducted a comprehensive analysis of both the original material characteristics and the available information on phase-structural transformations during cooling, glass transition and crystallization of melts, with detailed tracking of their ordering with using the methods as synchrotron X-ray diffraction, scanning electron microscopy, differential scanning calorimetry measurements, and with the interpretation of data by molecular dynamic simulation and thermodynamic calculations.
Keywords: melts, amorphous alloys, glass transition, X-ray diffraction, differential scanning calorimetry, medium order, structural factor, heat capacity, hidden liquid transitions, viscosity, diffusion, crossover.
Kushnarev B.O., Khludkova L.S.
Gas-sensitivity of tin dioxide thin film to kerosene vapours at room temperature – page 420
Abstract: The results of experimental studies the gas sensitivity of SnO2 thin films to kerosene vapor at room temperature in an atmosphere of dry and wet air are presented. The presence of water vapor in the surrounding atmosphere does not significantly affect the gas sensitivity of thin films to kerosene vapor. It is suggested that the process of oxidation of unsaturated hydrocarbons on the surface of tin dioxide has an autocatalytic character.
Keywords: gas-sensitivity, tin dioxide, thin films, kerosene vapors, room temperature.
Laipanov M.Z., Manukyants A.R., Sozaev V.A., Khubolov B.M.
Diffusional interaction in tin film – nickel base system – page 427
Abstract: In this work a Sn film was deposited on the nickel base of NP-2 sort in vacuum and bimetal nickel-tin compositions have been received. Eutectic formations, arising at the surface of tin film owing to a diffusional cooperation with the nickel base have been found by the scanning electron microscopy method. The X-ray-phase analysis of tin film was performed by using the small-angle scattering.
Keywords: bimetal compositions, diffusional of interaction, eutectic, films.
Magomedov M.N.
On the variation of the baric properties with a decrease in the size of a silicon nanocrystal – page 434
Abstract: Properties of a nanocrystal are calculated by means of the Mie-Lennard-Jones pair interatomic potential and the RP-model of the nanocrystal. The state equation P(v/v0, T) and the baric dependences for the lattice and for the surface properties both for macro- and for nano-crystals of silicon are found. A changes in the properties both at isochoric (v/v0 = 1) and at isobaric (P = 0) decrease in the number of atoms in a cubic nanocrystal at the different temperatures were studied.
Keywords: nanocrystal, the state equation, isochoric, isobaric, silicon.
Magomedov R.A., Akhmedov E.N., Meilanov R.R., Beybalaev V.D., Aliverdiev A.A.
Calculations of thermophysical characteristics of xenon – page 446
Abstract: On the basis of a generalization of thermodynamics in fractional derivatives and some analytical expressions obtained, taking into account the second virial coefficient B, we calculated thermophysical characteristics of a noble gas xenon Xe: entropy S and isochoric heat capacity CV. The calculated thermophysical parameters of exemplifying on xenon at temperatures 500, 1000, 1400, 2000 К in the pressure range from 0,1 to 90 MPa are given.
Keywords: thermodynamics, fractional derivative, fractal equation of state, entropy, isochoric heat capacity.
Malyshev M.D., Baburkin P.O., Adamyan A.N., Pakhomov P.M., Komarov P.V.
Simulation of the maturation process cystein-silver solution – page 453
Abstract: In this paper, the process of maturation of an aqueous solution of L-cysteine and silver nitrate using the method of atomistic molecular dynamics is investigated. To study the maturation process, an atomistic model of the solution was developed. The study allowed to obtain new data on the structure of silver mercaptide clusters and the role of their structural features in the process of further self-organization.
Keywords: hydrogel, supramonomer, computer simulation, atomistic model.
Mikitchuk E.P., Kozadaev K.V.
Convergence for simulation of surface nanostructure optical properties using finite integral technique – page 460
Abstract: Computer model of 2D-monolayer of noble metal nanoparticles on the solid substrate in the air surrounding is improved. Convergence for simulation of surface nanostructure optical properties using finite integral technique is studied by means of electromagnetic far-field analysis as well as re-calculation of scattering matrices obtained with finite integral technique. Both simulation residual and time is estimated for named approaches.
Keywords: surface nanostructure, monolayer of metallic nanoparticles, finite integral technique, surface plasmon resonance.
Musskaya O.N., Kulak A.I., Krut’ko V.K., Glazov I.E.
Adsorption-structural properties of calcium phosphates xerogels obtained by liquid-phase synthesis – page 468
Abstract: It has been established that xerogels of basic and medium calcium phosphates obtained by dehydration of calcium phosphate gels in air at 20°C with water-removing agents, cryogenic treatment (at −18 and −196°C) are characterized by a high specific surface (up to 158 m2/g). It was found that high-temperature heating of calcium phosphates at 800−1200°C leads to a significant decrease in their adsorption capacity (ABET 10−17 m2/g).
Keywords: calcium phosphate xerogel, adsorption-structural properties, hydroxyapatite, tricalcium phosphate, brushite, carbonate hydroxyapatite.
Myasnichenko V.S., Kolosov A.Yu., Sokolov D.N., Davydenkova E.M., Sdobnyakov N.Yu.
Calculation of the surface energy of copper nanowires of different thickness and orientation – page 477
Abstract: The Monte-Carlo lattice method is used to search for the surface structure of crystalline copper nanowires of various orientations. Fragmentation of 3,3 nm thick wires into individual spherical nanoparticles is observed. When a nanowire with an initial orientation along the [100] crystallographic axis is rotated, its surface energy increases monotonically to a certain value of the angle of rotation, with a further decrease with orientation along the [110] axis. A dependence of the surface energy on the nanowire’s diameter was not revealed.
Keywords: surface, Monte Carlo method, tight-binding potential, crystal lattice, nanowire, Rayleigh-Plato instability, fragmentation.
Nagorny Y.E., Politaev D.N.
Investigation of mechanical properties of silicane in the valence force field model – page 485
Abstract: Numerical simulation of mechanical properties of silicene samples are made in the valence force field model. The dependences of elastic modules on linear dimensions are found. The results are compared with those obtained in the of central force field model. Behavior of the corresponding graphs is similar. At the same time, a lag of values of the elastic modules received within the valence force field model in comparison with the central forces field model was observed. The lag in question accrues with growth of the sample sizes.
Keywords: central force field, valence force field, silicene, Young’s modulus, Poisson’s ratio.
Nemygina N.A., Bahvalova E.S., Buchma E.V., Smirnov I.S., Nikoshvili L.Zh., Sulman E.M.
Influence of local surface plasmon resonance on behavior of polymer-stabilized bimetallic nanoparticles in Suzuki cross-coupling reaction – page 492
Abstract: This paper is devoted to investigation of the effect of light in the visible spectral range on the activity of mono- (Au, Pd) and bimetallic (Au−Pd) catalysts. Electron microscopy data showed that nanoparticles with a core-shell structure are formed during the synthesis of a bimetallic catalyst. As a result of the testing of mono- and bimetallic samples in the Suzuki reaction between 4-bromoanisole and phenylboronic acid under optimum conditions, it was found that the activity of the bimetallic catalyst increases markedly when the light response is carried out by the occurrence of a local surface plasmon resonance, which is supposed to accelerate the stage oxidative addition of 4-bromoanisole to palladium.
Keywords: Suzuki cross-coupling reaction, gold, palladium, bimetallic catalyst, hypercrosslinked polystyrene, local surface plasmon resonance.
Orakova M.M., Mustafaev G.A., Nagaplezheva R.R.
Study of wetting the surface of silicon with NaCl-water solution – page 501
Abstract: The dependence of the water runoff angles from the silicon surface on the conditions of their preparation is investigated. The objects of investigation were single-crystal silicon plates KDB-10 with orientations (111) and (100). It is shown that the use of ethanol in the preparation of plates improves wetting with water. It is also established that small doses of NaCl in water do not affect the angle of the droplet flow.
Keywords: adsorption, drain angle, wetting angle, surface tension, Auger analysis.
Pan’kin N.A., Bataykina I.A.
Investigation of the bombardment of low-energy isomers of Tin clusters (n = 7, 13, 15, 19) by titanium atoms: molecular dynamics simulation – page 506
Abstract: The process of bombardment of low-energy isomers of Tin (n = 7, 13, 15, 19) clusters by titanium atoms is considered by molecular dynamics. It is shown that the initial cluster temperature (up to 500 K) does not influence the final results. Ion bombardment leads to the destruction of the initial cluster structure with the release of smaller particles. A significant fraction of the spray/decomposition products are monomers and dimers.
Keywords: isomer, bombardment, distribution functions, cluster.
Pan’kin N.A., Mishkin Vl.P.
Electron microscopy of Cu – SiC composites: a cold-molding and solid phase sintering – page 517
Abstract: Cu − SiC composites were studied by scanning electron microscopy after processes of molding and a heat treatment. After pressing, plastic deformation of copper particles and traces of destruction of silicon carbide (cracks and debris) are observed. After the solid-phase sintering, formation of a porous structure in the matrix material is noted without significant changes in the filler particles. Data on the distribution of chemical elements near the SiC − Cu interface indicate an insignificant effect of diffusion processes.
Keywords: composite, electron microscopy, copper, silicon carbide, microstructure, pores.
Petrik G.G.
A modelling approach to the choice of the equations of state of analogues of three series – page 524
Abstract: Within the framework of a simple molecular thermodynamic model, the problems of comparing the equations of state and the choice of analogues in three sets are analyzed: equations based on the model of interacting point centers, van der Waals type equations, and Martin equations obtained on the basis of translation by volume.
Keywords: simple equations of state, cubic equation, model of interacting point centers, volume translation, control parameters, choice of optimal equations of state.
Polukhin V.A., Kurbanova E.D., Belyakova R.M., Rigmant L.K.
The effect of hydrogenation on the processes of structuring and vitrification of suppercooled melts – page 535
Abstract: There have been considered the characteristics and structure forming of amorphous and nanocrystalline binary and ternary alloys based on Pd, as well as high-entropy Zr − Cu (Ni, Ti) compositions based on binary Ni − Ti, Ni − V and ternary Zr − Cu − Ti systems, which are difficult to manufacture, however, can significantly improve the economic efficiency of the processes of separation, purification of hydrogen and its safe storage. The analysis of the formation specificities of stable functional structures of membrane amorphous and nanocrystalline alloys in depending on their ability to hydride formation was also carried out.
Keywords: molecular dynamics, metallic glasses, vitrification, nanocrystalline alloys, transition metals, hydrogenation, clusters, short-range ordering, medium and long-range order.
Redel L.V., Gafner Yu.Ya., Gafner S.L.
Structural stability of small FCC – magic silver clusters for plasmonic applications – page 542
Abstract: One of the new applications of silver nanoparticles is their use in plasmon applications, which are determined by the strong interaction between the electromagnetic wave and free electrons in nanostructures. Particles of a metal with a size smaller than the wavelengths of visible light can strongly absorb light due to the phenomenon of surface plasmon resonance, due to the collective oscillation of conduction electrons. The frequency and intensity of the plasmon resonance depends on the distribution of the polarization charge in the nanostructure, which, in turn, is determined by the shape and structure of the nanoparticle. Thus, control of the structure of the metallic nanostructure allows you to control the wavelengths of light that it dissipates and absorbs.
Keywords: nanoclusters, silver, structure, computer simulation, tight-binding.
Savenko V.I., Samkanashvili D.G.
Nanoscale diagnostics of the «chicken wire» structure on the electron image of microchannel plates exposed to photoelectron scrubbing – page 550
Abstract: This paper presents the results of investigation of experimental prototypes of microchannel plates after photoelectron scrubbing. In the case of photoelectron scrubbing microchannel plate parameters are influenced mainly by the electron processing. The UV light influence on microchannel plate performance is insignificant when there is no voltage supply. Nano-scale contamination which exists in small amounts at some multi-boundaries is cleaned off when exposed to the input current.
Keywords: microchannel plate, photoelectron scrubbing, UV radiation.
Savenko V.I.
Effect of electronic irradiation on properties, composition of lead-silicate glasses and coefficient of secondary electron emission on their surface – page 557
Abstract: The paper discusses the effectiveness of methods for degassing surfaces of lead-silicate glasses by electron irradiation (treatment) in order to increase the efficiency of secondary electron emission. Changes in the properties and composition of the processed materials as a result of additional effects (heat treatment, reactions with ethyl alcohol, etc.) are revealed. Chemical compounds and elements formed as a result of impacts on the surface of lead-silicate glasses are described. The effect of sample storage on a further change in the secondary electron emission coefficient was studied.
Keywords: electron irradiation, electron processing, lead-silicate glass, processed surface of lead-silicate glasses, secondary electron emission, amplification.
Sverdlik G.I., Ataeva A.Y., Kambolov D.A., Ataev A.R.
Classification and selection of barbage equipment for collecting dust nanoparticles – page 566
Abstract: А classification of bubblers according to a constructive feature has been developed on the basis of literature analysis and patent search. A comparison of different types of bubblers has been performed according their ability to effectively capture small particles, including nanoparticles. For this purpose it is recommended to use a jet bubbler developed in the North Caucasian Institute of Mining and Metallurgy (State Technological University) on the basis of the patented distribution cup cap plate.
Keywords: gas emissions, nanoparticles, bubbler classification, jet bubbler, foam regime, experimental installation.
Sdobnyakov N.Yu., Samsonov V.M., Bazulev A.N.
Size of metal nanoparticles as a factor of their stability – page 576
Abstract: Using available experimental data on evaporation rates for metal nanoparticles and shrinkage rates for vacancy pores, evaluations have been performed of the particle size ranges where the linear dependence σ = Kr between the surface tension σ and the particle radius r. The reliability intervals have been found for the proportionality coefficient K. The results obtained are compared to evaluations by E.N. Vitol (1992). On the bases of the results of these evaluations a conclusion has been confirmed that a thermodynamic stability condition obtained before is fulfilled for nanoparticles of all metals considered in the paper.
Keywords: metal nanoparticles, Rusanov’s formula, stability, evaporation of nanoparticles, shrinkage of vacancy pores.
Sidorov N.V., Shuvalova A.M., Teplyakova N.A., Palatnikov M.N.
Particularities of the structure and photoelectric fields of LiNbO3 : Zn crystals – page 584
Abstract: Values of intensities of photovoltaic and diffusion fields were determined in congruent LiNbO3 crystals both nominally pure and doped by zinc due to parameters of a photoinduced light scattering. A change in electro-optical properties of LiNbO3 : Zn crystals at an increase in the zinc concentration to a threshold value was shown to be determined by particularities of oxygen octahedra deformations and an order of cation sublattice structure units along the polar axis.
Keywords: single crystal, lithium niobate, doping, photoinduced light scattering, photorefractive effect, photovoltaic field, diffusion field.
Simakov V.V., Sinev I.V., Osyko I.D., Shcherbakova E.A., Grebennikov A.I.
I-V characteristics of gas sensors based on tin dioxide thin films in wet air at room temperature – page 591
Abstract: In this work cyclical I−V characteristics of a gas sensor based on tin dioxide thin films in wet air at room temperature has been studied. It was demonstrated that cyclical voltage variation leads to redox reactions on the surface of the gas sensor active layer. Redox reaction potential does not depend on the gas concentration in an analyzed gas probe. Therefore, the redox potential can be used as an identifying agent.
Keywords: I−V characteristics, gas sensors, thin films, tin dioxide, room temperature, gas mixture identification.
Skachkov V.М., Pasechnik L.А., Skachkova О.V., Yatsenko S.P.
Diffuzionno-hardening solders based alloy gallium-indium-tin and powder of metal PCTSP5 reinforced with titanium – page 600
Abstract: The paper considers a new composition of diffusion-hardening solder based on a low-melting gallium alloy and copper-tin spherical powder (PCTSP5). The influence of the powder filler – titanium composition on the structure and properties of solder for expanding the areas of use is investigated. Strength properties, microstructure, thermal stability of the samples were studied.
Keywords: metal powder, composite diffusion-hardening alloys, solders, structure, properties, microhardness, differential thermal analysis.
Starodub O.R., Voskresenskij V.M., Sidorov N.V., Palatnikov M.N.
Mathematical simulation of cluster formation in lithium niobate crystals with introduction of the impurity ion – page 609
Abstract: Processes of clustering in a lithium niobate crystal (LiNbO3) were studied. It is shown that the cluster with the ratio Li / Nb ≈ 0,945, which is close to the ratio of lithium to niobium in a congruent crystal, is the most energy-efficient cluster. It was found that because of the loss of electroneutrality, a cluster of stoichiometric composition can not exist. It is established that there is an optimal relationship between the energy of the cluster, its size and the Li / Nb ratio.
Keywords: lithium niobate, modeling, clusters, vacancy models, sublattice defects, single crystals, ferroelectrics.
Talyzin I.V., Samsonov M.V., Vasilyev S.A., Pushkar M.Yu., Dronnikov V.V., Samsonov V.M.
Molecular dynamics research of size dependence of the melting temperature of silicon nanoparticles – page 618
Abstract: Size dependence of the melting temperature of Si nanoparticles has been investigated combining molecular dynamics and thermodynamic simulations. The results of the atomistic simulation obtained using the Stillinger-Weber potential agree with the results of other authors and with the thermodynamic simulation results based on Thomson’s formula. These results predict that the melting temperature Tm of Si nanoparticles diminishes with increasing their reciprocal radius R-1 following to the linear law. The available experimental data predict much lower values of Tm, including underestimated values of the limiting value Tm(∞) found by means of the linear extrapolation of experimental dots to R-1 → 0 (i.e. to the particle radius R → ∞), and the underestimation of Tm(∞) ranges from 200 to 300 K in comparison with the melting point 1688 K of the bulk crystalline Si. Taking into account the obtained results and their comparison with available results of other authors, a conclusion is made that molecular dynamics results, obtained by using the Stillinger-Weber potential, should be more adequate than the available experimental data on the melting temperature of Si nanoparticles.
Keywords: silicon nanoparticles, melting temperature, size dependence, molecular dynamics, thermodtynamics.
Teplyakova N.A., Sidorov N.V., Palatnikov M.N.
Defective structure and photorefractive properties of double doped crystals LiNbO3 : Fe : Mg and LiNbO3 : Fe : Zn – page 628
Abstract: A comparative analysis of photorefractive properties was carried out for congruent, stoichiometric and double doped lithium niobate crystals: LiNbO3 : Fe(0,009) : Mg(5,04) and LiNbO3 : Fe(0,02) : Zn(4,34) mol %. These crystals are different in defect types, which are responsible for the effect of photorefraction. Band gap was shown to be minimal for double-doped crystals, photorefractive effect to be the same as for stoichiometric crystals, and photoinduced light scattering was not observed.
Keywords: single crystal, lithium niobate, doping, photoinduced light scattering, photorefractive effect, band gap.
Uglev N.P., Zamorin I.N., Uglev S.N., Smirnov S.A., Selivanov A.M.
Distribution of components of jewelry alloy in the bulk of metal castings – page 636
Abstract: The process is investigated of stratification of a quaternary jewelry alloy within the height of a vertical metal crucible. The concentration distribution of the alloy components near the surface of castings, as well as the features of the structure formation of the solid alloy is studied. It is shown that the distribution of metals in the volume generally corresponds to known data for other metallic melts. A direct correlation of the microhardness to the alloy composition is revealed.
Keywords: multicomponent metal melt, stratification, distribution of components, microhardness, long-range order, swarm of clusters, superfluidity.
Khubolov B.M., Podlinov V.P., Bagov A.M.
Study of materials for electrochromic devices: physical and chemical methods – page 646
Abstract: The methods of producing and investigation of electro-chromically-sensitive thin films of tungsten oxide bronzes have been considered in peer-review. The researches allowing one to make deductions on the particular models of the physical process laying in the basis of the electrochrome effect have been described in detail. The most important problems of the further studies on the complex oxides of the transition metals for obtaining applied results capable to start the highly effective technology of the electrochrome devises have been formulated.
Keywords: electrochromism, oxide potassium-tungsten bronze, thin films, spectral characteristics, single crystals, electrovacuum deposition, technological parameters of deposition.
Khubolov B.M., Podlinov V.P., Bagov A.M.
Optical characteristics of thin films of potassium-tungsten bronzes – page 656
Abstract: The spectral dependences of the optical density of thin amorphous film of oxide potassium-tungsten bronze of hexagonal structure and composition K0,3WO3 have been measured. The central problems of interpreting of optical spectra of oxide tungsten bronzes have been postulated.
Keywords: tungsten-potassium oxide bronze, thin films, spectral characteristics, discrete evaporation, absorption centers.
Shepelevich V.G.
Grain structure of bismuth-tin alloys, additional doping with indium – page 665
Abstract: Results of investigation of the grain structure of bismuth-tin additionally doped with indium are presented. The foils have microcrystalline structure. Average sizes of bismuth ones were less than 2 μm and of tin ones were of 3 μm. The bright (10 1 2) textures of bismuth and (100) of tin are formed in the foils.
Keywords: high speed crystallization, foil, grain, grain boundary specific surface, tin, bismuth, indium.
Shermetov A.Kh., Shokarov A.A., Ponezhev M.Kh., Sozaev A.V., Karamurzov B.S.
Wetting of aluminum and copper substrates by lead – nickel melt – page 671
Abstract: In this paper, the task of obtaining new solders for brazing nickel and its alloys. Polyterms of wetting angle for Pb − Ni melts in the range from the melting point to 940 K on copper substrates and up to 900 K on aluminum were studied and wetting thresholds were detected: wetting of copper substrates starts at 640 K, and aluminum substrates are not wetted by the abovemelts.
Keywords: wetting angle, aluminum, nickel, copper, temperature of wetting threshold.
Shomakhov Z.V., Shomakhova R.A., Molokanov O.A., Karmokov A.M.
Diffusion of potassium ions and electrical conductivity in glass for electronic optics – page 677
Abstract: The results of a study of the electrical conductivity and diffusion of potassium ions in borate-barium glass (C78–5) – 2,2% SiO2 57,8% B2O3 8,2% K2O 19,0% BaO 3,5% CaO 8,8% Al2O3 0,5% MgO with the passage of electric current through the sample. The time dependences of self-diffusion coefficients are calculated for the transmission of an electric current at a constant temperature.
Keywords: electrical conductivity, ion diffusion, borate-barium glass, isothermal annealing.
Shcherbakova V.B., Sadovskaya L.Yu., Logvinovich A.S., Sviridova Т.V., Sviridov D.V.
Photo-accumulating composite materials based on heteropolymolybdates – page 683
Abstract: It was shown that modifying titanium dioxide particles with ammonium 6-molybdoferrate (II) and ammonium 6-molybdonickelate (II) gives the photocatalyst the ability to accumulate a photogenerated charge and maintain oxidative activity for some time after ultraviolet irradiation. In this case, heteropolymolybdates not only ensure the accumulation of a photoinduced cathodic charge, but also the conversion of hydrogen peroxide, formed during the oxidation of reduced forms of heteropolymolybdates with air oxygen, to highly active hydroxyl radicals.
Keywords: nanodispersed titanium dioxide, photochemistry, polycondensation of oxoacids of transition metals, ultraviolet radiation, heteropolymolybdates.
Yurov V.M., Guchenko S.A., Laurinas V.Ch.
Thickness of the surface layer, surface energy and atomic volume of the element – page 691
Abstract: The thickness of the surface layer of an atomically pure metal, which turned out to be equal to 5-6 nm, was calculated in this work. It is shown that the thickness of the surface layer is determined by one parameter – the atomic volume of a chemical element. A simple relationship between the surface energy of a metal and its melting point is obtained. All the relationships obtained are in good agreement with the experimental data.
Keywords: surface layer, nanostructure, surface energy, atomic volume, size effect.