Bulk nanostructured BixSb1−xTe3 based material was fabricated with spark plasma sintering (SPS) method. The starting powders with a particle size of 10—12 nm were prepared by ball milling. The regularity of fine structure changes as a function of sintering temperature in the 250—550 °C range was investigated by X−ray
diffractometry, scanning and transmission electron microscopy (TEM, HRTEM). For the first time coherent dispersion areas (CDA) size was found not to increase monotonously with sintering temperature, and at temperatures of above 400 °C the CDA size decreased as a result of repeated recrystallization. Apparently,
the structural changes are associated with a redistribution of intrinsic vacancy type structural defects during sintering.

Thermoelectric properties of (Bi,Sb)2Te3 nanostructured bulk material as a function of composition and spark plasma sintering temperature were investigated. The Bi0,4Sb1,6Te3 alloys at sintering temperature 450—500 °C with ZT=1,25—1,28 figure of merit was fabricated. Thermoelectric properties ad a function of
sintering temperature above 400 °C correlate with fine structure change. It was found that point structure defects introduce essential contribution to the formation of nanostructured material thermoelectric properties.

The angular dependence of the lateral component piesoresponse in Y−cut lithium niobate single crystals with a regular domain structure was investigated in piezoresponse force microscopy mode. It is shown that visualization of the domain structure is determined by the orientation of the X direction of the crystal relative to the scan direction: the greatest contrast between domains with opposite orientation of the polarization vectors takes place at locations along an X−direction line and the direction of scanning.

Multicomponent piezoelectric crystals of langasite family were studied. The process of crystal growth and crystal structure were investigated. X−ray diffraction and topography were used to study the acoustic properties of crystals. The possibility of application of the piezoelectric crystals in high−temperature SAW−sensors was demonstrated.

Results of studying coercive force, optical absorption and lattice mismatch in single−crystal epitaxial magnetic garnet films are presented. It is shown that the reason of high values of both coercivity and optical absorption are the oxygen vacancies compensating Ca2+ ions and lattice mismatch stress. Methods of inducing high−coercivity state in Bi−containing garnet films through doping by bivalent impurity ions, through mismatch stress or through treatment in negative corona discharge are proposed. Merits and demerits of these methods are discussed and their comparison is carried out.

We derive a mathematical model for the composite material extrusion process which describes the main features of the resulting material stress−strain state. The extrusion process includes extrusion of a cylindrical billet of pressed powder through a die of desired geometry. Die geometrical parameters and process speed can be preset. The computational model is based on combined elastic−plastic body approximation. The numerical
technique uses a finite element approximation on Lagrangian grid, which changes over time with changes in sample shape. To perform it we use adaptive grid units generation in areas of sample high stress and strain. The calculations were performed in Crystmo/Marc software package. We study the basic features
of stress−strain state of the material obtained at different stages of extrusion process.

An analytical solution of an avalanche current in p—i—n−structures is obtained. The impurity level and a generation−recombination phenomena are taken into consideration.P—i—n–structures current−voltage characteristic is derived. The results explain pattern formation and hysteresis under strong electrical field.

Studies of test characteristics of the test thyristor structures based on CZ−Si <P, Ge> exposed to gamma irradiation showed a much higher radiation resistance of this device compared with those of the reference structures obtained under similar conditions on single crystals of silicon not doped with germanium.

In0,01Ga0,99As/In0,56Ga0,44P /Ge structures for the first tandem of three−tandem A3B5/Ge solar cells were synthesized using MOS hydride epitaxy. The p—n–junction was formed by boron diffusion into gallium doped germanium. Phosphorus and gallium profiles in germanium were measured using SIMS. We show that
changes in the phosphine flow do not affect the phosphorus distribution and the p—n–junction depth in the germanium stage.

In this paper we investigated the effect of reducing the LED quantum efficiency at increasing the current density. Reasons influencing this effect are determined. We show methods to reduce this effect and the positive results of using the silicon substrates in nanoheterostructures for light−emitting diodes.

Nanoporous and nanotubular titanium oxide layers were fabricated by electrochemical etching in a mixed organic–inorganic electrolyte. The process of layers formation was investigated in−situ using the electrochemical impedance spectroscopy method. The experimental data show that, except for an initial stage of electrolytic etching, the impedance of a porous titanium oxide layer during almost the entire process is determined by the impedance of a small contact area of electrolyte/titanium oxide at the bottom of the nanoporous and nanotubular layers. The observed higher resistances of space charge region in the titanium oxide layer in comparison with the resistance of charge transfer at the electrolyte/TiOx boundary testify that the growth rate of porous and nanotubular layers is limited by the diffusion of titanium and oxygen ions through the oxide layer, and not by the diffusion of ions in the electrolyte.

Novel materials based on carbon nanocrystal material and metal−carbon nanocomposites which have specific properties and can be used for manufacturing electronic, electrochemical and sensor devices and catalysts are proposed for developing electronics

«Silicon−on−insulator» (SOI) structures irradiated with Ar+ ions with an energy of 100 keV and doses of 2 ⋅ 1013 and 4 ⋅ 1013 cm−2 were investigated by high−resolution X−ray diffraction and Rutherford backscattering spectroscopy methods.
Such a choice of implantation energy allowed us to set the maximum of projected ions length in the middle of the silicon layer and to minimize possible changes of electric and elastic force fields of the internal dielectric during irradiation. The implantation was accompanied by an irradiation using UV lamp (photoexcitation in situ) with a flux of 25 mW ⋅ cm−2. It was found that in the case of low doses the photoexcitation leads to cluster formation both near the sample surface and in the area of maximum strain. At the dose of 4 ⋅ 1013 cm−2, when surface amorphization starts, the photoexcitation no longer influenced the redistribution of radiation−induced defects. The photoexcitation favors the sink of interstitial type defects towards the surface.

The capabilities of an XMD−300 diffractometer were explored in three measurement setups, i.e. sliding primary beam, diffracted primary beam, θ–2θ setup for the crystalline perfection investigations of semiconductor heterostructures (SOS, SOI, AlGaN/GaN/Si, ion implanted silicon layers). We show that measurements
using these three setups in scattered radiation and at direct validity of Bragg’s diffraction condition allowed receiving diffraction interference patterns simultaneously from the crystal lattice of several layers and interferential picks of maximum intensity for each individual layer.