Structure and mechanical and electrochemical properties of ultrafine-grained Ti

A study is conducted into the microstructure and physico-mechanical properties of ultrafine-grained titanium produced by severe plastic deformation using the method of equichannel angular pressing. The effects of thermal and mechanical treatment on these characteristics are investigated. The possibility of forming mechanical properties in titanium that compare well with those of highly doped titanium alloys is shown. Institute for Strength Physics and Materials Science; Siberian Physical-Technical Institute at Tomsk State University; Institute of Physics of Advanced Materials at UFA Aviation Technology University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 77–85, January, 2000.     

Study of the Elementary Growth Processes During Vapor-Phase Epitaxy of Semiconducting III–V Compounds

A review of studies performed at the V. D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University and aimed at obtaining detailed information on the elementary growth processes proceeding at the crystallization front during vapor-phase epitaxy of semiconducting III–V compound films is presented in the paper. The general approach to the problem and methods of its solution are described. Results of investigations of the adsorption layer composition, surface diffusion processes, and incorporation of growth components into a crystal are presented. The mechanism of epitaxial layer growth in semiconducting III–V compounds is discussed.     

Distribution of electric field in GaAs diffused structures doped by iron or chromium

An analysis based on numerical calculations has been done for the distribution of an electric field in GaAs diffused by chromium or iron-doped structures. First, a calculation has been carried out for the non-uniform impurity distribution using experimentally measured Fe and Cr profiles. It is shown that a ν-n-junction is formed in chromium-doped structures, and a π-n-junction is formed in iron-doped ones. A conclusion is made that these junctions are graded. V. D. Kuznetsov Siberian Physical-Technical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 43–48, March 1999.     

Electronically excited states of phenol and its water complexes and photoprocesses in them

Energies of electronically excited states of phenol and its water complexes have been calculated with the use of the method of intermediate neglect of differential overlap (INDO) and the theory of intermolecular photophysical processes. The fluorescence quantum yield has been investigated as a function of the excitation energy. It is shown that the experimental dependence of the fluorescence quantum yield on the excitation energy is determined by the photolysis of phenol. The photoreaction of the breaking of the OH bond has been considered. Its mechanism and electronically excited states in which it runs have been established. V.D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 3–7, May, 1999.     

Investigation of the thermodynamic efficiency of magnetic cooling cycles in the region of spinorientational transformations in hexagonal ferrimagnets

The feasibility of using hexagonal ferrimagnets with spin-orientational transitions as the working body of a magnetic refrigerator is studied. The temperature dependence of the magnetic part of entropy and its change in crystal magnetization along various directions are calculated. The thermodynamic efficiency of magnetic cooling cycles in the vicinity of orientational transitions is estimated. Optimal magnetization fields and working temperature interval are determined. The results of calculations are compared with experimental investigations of the magnetocaloric effect for theCo _0.62 Zn _1.38-W compound. V. D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 9–13, February, 2000.     

Dissipation of energy in the contact of materials having shape memory

Problems of dissipation of energy in the contact of bodies made of titanium nickelide are studied by the mechanocycling method. Under normal loading or joint action of normal and shearing forces the dissipation of energy ΔW, determined from the hysteresis loop area enclosed by the dependences pressure q—approach δ and shearing force τ-shift Δ, is several times higher than that of traditional materials, and the dependence τ-Δ is nonmonotonous in character and has some extreme points. The peculiarities in the formation of hysteresis loops are established. The obtained results are explained in the context of thermoelastic martensite transformations and the theory of contact interaction. V. D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 83–87, March, 1999.     

Influence of positions of boron, carbon, and nitrogen atoms in the FCC lattice of iron on the characteristics of interatomic interaction

A semi-empirical model is proposed for calculating the characteristics of interatomic forces for virtualFeB, FeC, andFeN compounds on the basis of their electronic structure as functions of the positions of interstitial atoms. On the example of these compounds the universal character of the dependence of the bulk modulus of elasticity on the electronic density in the interspherical space found previously derived earlier in the literature for pure base and transition metals has been demonstrated. It has been found that the arrangements ofB, C, andN atoms in the octahedral interstices are energetically more favorable in comparison with their arrangements in the tetrahedral interstices. The influence of individual properties of the interstitial elements on the calculated quantities is analyzed. V. D. Kuznetsov Siberian Physical-Technical Institute at the Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 40–44, April, 1999.     

Inhomogeneous polarizable medium as a model for an electron gas in a nonconducting crystal

The response of the electron system to an external perturbation in an insulating medium is considered in the context of the electron density functional method. The energy functional minimization relies on the proper choice of the trial function considering different spatial scales of the electron polarization. An efficient scheme for the density functional parametrization is suggested. The electron response to atomic displacements and external electric fields has been calculated for a simple model of electron polarization centers embedded into the homogeneous dielectric background. Good agreement with the experiment is achieved for the phonon spectra ofSi, Ge, and α-Sn. The electron density induced in the external homogeneous electric field is in good agreement with that calculated by the well-known ab initio methods. V. D. Kuznetsov Siberian Physical-Technical Institute at Tomsk State University. Translated for Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6 pp. 30–37, June, 1999.     

Structure studies on porous titanium nickelide made by high-temperature self-propagating synthesis

Structure studies are reported on martensite transformations in porous TiNi alloy made by high-temperatures self-propagating synthesis. The transformations occur over a large temperature range and are incomplete. The structure data are used in reconstructing the heat release during the transition, where it is shown that it is determined by the superposition of martensite transformations occurring locally at various temperatures. Tomsk State Architectural and Building Academy. Kuznetsov Siberian Technical Physics Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 20–24, January, 1997.     

Influence of nonhydrostatic stresses on the development of martensitic transformations and inelastic strains at various levels in Ti(Ni-Cu-Fe) polycrystalline intermetallic compounds

The levels of inelastic martensitic strain of polycrystals during a thermoelastic martensitic transformation under a load are discussed. The example ofTi(Ni-Cu-Fe) alloys with the B2 structure was used to study the role of microlevel and mesolevels in inelastic martensitic deformation during cooling of polycrystals under a load and loads in different initial structural states. V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Institute of Physics of Strength of Materials and Materials Science, Siberian Branch of the Academy of Sciences of the USSR, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, p. 35–46, January, 1998.     

Nontrivial conformally steckel metrics in einstein spaces

All isotropic conformally Steckel metrics are derived that satisfy the Einstein vacuum equations containing a Λ term and do not reduce to the purely Steckel type. The metrics allow the integration of the Hamilton-Jacobi equation for a massless particle by complete variable separation. Tomsk State Pedagogic University. Tomsk State University. High-Current Electronics Institute, Siberian Division, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 74–78, October, 1997.     

Structure and properties of epitaxial GaAs and InGaAs films grown by low-temperature molecular-beam epitaxy

We study epitaxial GaAs and InGaAs films produced by molecular-beam epitaxy in the temperature range 150–480°C and with various arsenic partial pressures. We determine the structural and electrophysical characteristics of the film (the excess arsenic, the crystal lattice parameter, and the carrier concentration and mobility) as a function of the growth conditions. The influence of annealing on the cluster-structure formation in low-temperature MBE films, and on their properties, is also studied. In low-temperature GaAs we find a characteristic microwave absorption signal indicating the presence of a superconducting phase. We discuss the possible nature of this phase with regard to clusters of gallium or an In-Ga alloy. Siberian V. D. Kuznetsova Physicotechnical Institute, Tomsk State University. Tomsk State University. Semiconductor Physics Institute, Siberian Division, Russian Academy of Sciences. A. F. Ioffe Physicotechnical Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika No. 9, pp. 37–45, September, 1998.     

基于GaSe和GaSe0.7S0.3单晶的单脉冲CO2激光倍频器

描述了使用电感储能发生器和半导体转换开关泵浦的工作波长为10.6μm的高效CO2激光器。给出了激光泵浦的非线性晶体GaSe和GaSe0.7S0.3的二次谐波振荡的实验数据和理论估算结果。结果显示,GaSe晶体在输入能量为180mJ时,最大能量转换效率为0.38%,倍频激光的峰值功率为8 kW。     

Classification of conformal steckel spaces in the vaidia problem

The classification of isotropic conformal Steckel spaces satisfying a system of Einstein equations in which the right-hand side is the energy—momentum tensor of an isotropic ideal liquid is considered. The complete solution of the problem is found for the case of a conformal Steckel space admitting of one isotropic Killing vector field and two Killing tensor fields, when these objects form a complete set. Tomsk State University. Tomsk State Pedagogical University. Institute of High-Power Electronics, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 48–53, August, 1996.     

Optimal localization of measurements in physical and technological applications

The problem of optimal spatial arrangement of measurement detectors is considered. An approach is suggested, based on convex quality criteria and the application of effective algorithms of convex Boolean programming.V. D. Kuznetsov Siberian Physicotechnical Institute at the Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 143–148, September, 1992.     

Wavelength tunable light filter. Choice of rotational axis position

The wavelength selected by a light filter is tuned by rotating the filter. The optimal positions are found for the rotational axis of a light filter used in different applications and meeting practical requirements. V. D. Kuznetsov Siberian Physicotechnical Institute at the State University, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 62–67, September, 1997.     

Distortion deformations in the B2-R phase transition in titanium nickel alloys

Based on x-ray analysis, we have calculated the lattice distortions in Ti-Ni-Me (Me=Rh, Co, Fe) alloys during the B2-R phase transition. We find that, during the transition, the deformation decreases as the concentration of the alloying component increases in Ti-Ni-Rh and Ti-Ni-Co. No such correlation is observed in the Ti-Ni-Fe alloys. Tomsk State Architecture-Construction Academy. V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 95–100, February, 1997.     

Soliton formation processes in optically dense media

Numerical methods are used to investigate the characteristics of soliton formation when optical pulses of arbitrary shape and duration propagate in resonantly absorbing media of large optical thickness. It is shown that a regime of soliton propagation in a resonant medium, characterized by a nonlinear Schrödinger equation model, changes to a self-induced transparency regime. Incoherent steady-state interaction conditions are then replaced by coherent interaction. This effect can be utilized to compress laser pulses.V. D. Kuznetsov Siberian Physicotechnical Institute at the State University, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 95–99, October, 1994.     

The use of a priori information in the statistical processing of experimental data

Methods are considered of improving the quality of the statistical processing of experimental data, owing to the use of both exact and approximately given a priori data.V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 136–142, September, 1992.