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


Author: norAdmin


THE EFFECT OF CALCIUM NITRATE ON THE PHOTOCHEMICAL FORMATION PROCESSES OF URANIUM NANOCLUSTERS IN THE SOLUTIONS OF URANYL PERCHLORATE IN ACETONE

D.S. Umreiko, A.I. Komyak, E.V. Vileishikova, A.P. Zajogin

Abstract: Using the electron absorption method, the effects exerted by the physical and chemical properties of calcium nitrate solutions on the photopolymerization processes of acetone and on the photochemical nanocluster formation due to the tri-, tetra-, and pentavalent uranium complexes with organic ligands have been studied on LED-illumination of UO2(ClO4)2⋅5H2O  solutions in acetone over the region 420-440 nm. The process patterns have been established.
Keywords: uranium, cations of metal, photochemical activity, electronic absorption spectra, acetone

CHANGING THE SHAPE AND STRUCTURE OF COPPER NANOCLUSTERS SYNTHESIZED FROM THE GAS PHASE

I.V. Chepkasov

Abstract: To analyze thermal effects on the shape and structure of the synthesized copper nanoparticles, their smooth heating in the temperature range from 100 to 1200 К was produced. It was concluded that as a result of short-term heating, there was a significant ordering of the internal structure of 70 % of agglomerated nanoparticles with the preferential formation of spherical shape.
Keywords: computer simulation, copper nanoparticles, the structure, the gas phase

SYNTHESIS AND STUDYING OF ACID-BASE PROPERTIES OF TiO -Ag 2 NANOCOMPOSITE

M.S. Shama, A.A. Kravtsov, A.V. Blinov, M.A. Jasnaja, D.G. Selemeneva

Abstract: This article is devoted to studying the acid-base properties of the surface of titanium dioxide and Ag nanocomposite based on it (TiOmodified nanosize silver) synthesized by sol-gel method.
Keywords: TiO2 nanoparticles, nanocomposite TiO – Ag 2 , the sol-gel method, acid-base properties, the indicating method

STRUCTURE, MICROHARDNESS AND THERMAL STABILITY OF RAPIDLY SOLIDIFIED Bi31Sn34Pb35 ALLOY

V.G. Shepelevich

Abstract: Results of investigations of structure, microhardness and stability of rapidly solidified Bi31Sn34Pb35 alloy are presented. Textured ε–phase and dispersive Sn and Bi particles are forming in rapidly solidified alloy. Ageing of foil course change of structure and increase of microhardness take place at the room temperature.
Keywords: rapid solidification, foil, alloy, phase, texture, microhardness, lead, tin, bismuth, ageing

CONSTRUCTIVELY TECHNOLOGICAL PRINCIPLES OF CAPACITIVE HUMIDITY SENSING Al2O3 NANOSTRUCTURES AND SENSITIVE PARAMETERS STUDY

D.L. Shimanovich

Abstract: Volumetric-surface variants of capacitive MDM (metal-dielectric-metal) structures of the vertical direction based on high-ordered matrices of free anodic porous alumina membranes for applications in humidity sensing elements were designed. The improved humidity sensitivity, reduced response and recovery time over a wide humidity range were obtained due to preparing of alumina membranes with open-ended and widened pores without the barrier layer. Such technological approach allows to eliminate the effect of electrolyte anions embedded in pore walls on adsorption and desorption processes in humidity sensing elements.
Keywords: aluminum, electrochemical anodization, porous alumina, barrier layer, membrane, nanostructured material, humidity sensing element, adsorption, response time, recovery time, sensitivity

Modelling of the copper cluster’s growth: topological description, stability and occurrence in intermetallics

A.A. Esser1, V.S. Myasnichenko2,3, L.A. Myasnichenko4, N.Yu. Sdobnyakov3
1 Межвузовский научно-исследовательский центр по теоретическому материаловедению (МНИЦТМ), ФГАОУ ВО «Самарский национальный исследовательский университет имени академика С.П. Королева»
2 Рубцовский индустриальный институт (филиал) ФГБОУ ВПО «Алтайский государственный технический университет имени. И.И. Ползунова»
3 ФГБОУ ВО «Тверской государственный университет»
4 ФГБУН «Институт горного дела имени Н.А. Чинакала» СО РАН

Abstract: In this paper, we study the structure of the modeled copper clusters containing up to 100 atoms. The most stable configuration were determined by calculating the internal potential energy with using the Cleri-Rosato many-body potential. Using ToposPro we have performed the topological analysis of the Cu4 – Cu100 clusters, as a result one can see that the modeled clusters have the certain types of internal polyhedral cores. With increase of the size of the nanoclusters their occurrence in intermetallics monotonically decreases. The sequential topological growth of copper nanoclusters with internal icosahedron was realized only in certain size ranges.
Keywords: cluster, intermetallic compound, structure, topology

THE SIZE DEPENDENCE OF SURFACE TENSION AND HOMOGENEOUS NUCLEATION OF CRYSTALS

V.M. Yurov

Abstract: In this paper we show that, despite various modifications and clarifications of the classical theory of nucleation, it is far from matching the experimental and theoretical data. The main reason for this is due to not taking into account the size dependence of the surface tension of the emerging centers of crystallization. For many metals the critical radius of the homogeneous crystal formation were calculated.
Keywords: crystallization center, surface tension, critical radius