Properties of (Bi2Sb5Se3Te6I3)1 ? xMx (M = Ce, Pr) solid solutions

The effect of doping with Ce and Pr on the physicochemical properties of Bi₂Sb₅Se₃Te₆I₃ has been studied using differential thermal analysis, X-ray diffraction, microstructural analysis, microhardness tests, and density measurements. The results demonstrate that n-type Bi₂Sb₅Se₃Te₆I₃ dissolves 3.5 at % Ce. The Bi₂Sb₅Se₃Te₆I₃-Ce system has a eutectic at 10 mol % Ce, which melts at 360°C. The Pr solubility in Bi₂Sb₅Se₃Te₆I₃ is 4 at %. This system has a peritectic point at 10 at % Pr, with a peritectic temperature of 550°C.     

Phase relations and properties of alloys in the SnSe-DySe system

Phase relations in the SnSe-DySe system have been studied using differential thermal analysis, X-ray diffraction, microstructural analysis, microhardness tests, and density measurements, and its T-x phase diagram has been mapped out. The SnSe-DySe system contains a new ternary compound with the composition DySnSe₂, which crystallizes in orthorhombic symmetry with unit-cell parameters a = 5.74 ± 0.02 Å, b = 10.49 ± 0.03 Å, and c = 11.66 ± 0.05 Å (Z = 7, V = 702 ų, measured density ρ_meas = 7.02 g/cm³, X-ray density ρ_x = 7.26 g/cm³). In addition, the system contains SnSe-based solid solutions, Sn_{1 ? x} Dy _x Se (up to 4 mol % DySe). Their electrical conductivity and thermoelectric power have been measured as functions of temperature.     

Growth of perfect-crystal Si-Si1−x Gex-(Ge2)1−x (InP)x structures from the liquid phase

Structures comprising Si-Si_1−x Ge_x-(Ge₂)_1−x (InP)_x with an intermediate Si_1−x Ge_x buffer layer were grown on silicon substrates. Morphological examinations, scanning patterns and diffraction spectra, and also the electrophysical and luminescence properties of the heterostructures were used to show that the crystal perfection of these structures depends on the choice of liquid-phase epitaxy conditions. Pis’ma Zh. Tekh. Fiz. 25, 37–40 (December 26, 1999)     

Dynamic effects during thermoelastic martensitic transformations in TiNiCu alloys

Spontaneous periodic oscillations in the phase transformation rate during a system evolution toward a stationary state are observed in TiNiCu alloys. The conditions of manifestation and amplification of these oscillations are established and possible applications of this phenomenon are considered.     

Thermal conductivity of Er<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Sn<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Se (<Emphasis Type="Italic">x</Emphasis> ≤ 0.025) solid solutions

The thermal conductivity of Er _x Sn_{1 ? x} Se solid solutions has been measured at temperatures from 80 to 360 K. The results have been used to evaluate the electronic and lattice components of thermal conductivity for elastic carrier scattering, parabolic bands, and arbitrary degeneracy. With increasing erbium content and temperature, both the electronic and lattice components decrease considerably. Long-term annealing increases both components. It follows from the present experimental data that heat conduction in Er _x Sn_{1 ? x} Se is mainly due to phonons and that the observed rise in thermal resistance with Er content is due to phonon-phonon and paramagnetic-ion scattering.     

Dynamics of the Moving Load Acting on the Hydro-elastic System Consisting of the Elastic Plate,Compressible Viscous Fluid and RigidWall

The subject of the paper is the study of the dynamics of the moving load acting on the hydro-elastic system consisting of the elastic plate, compressible viscous fluid and rigid wall. Under this study the motion of the plate is described by linear elastodynamics, and the motion of the compressible viscous fluid is described by the linearized Navier-Stokes equations. Numerical results are obtained for the case where the material of the plate is steel, but the fluid material is Glycerin. According to these results, corresponding conclusions related to the influence of the problem parameters, such as fluid viscosity, plate thickness, fluid depth, fluid compressibility and initial stresses on the inter-phase normal stress and normal and tangent velocities of the fluid caused by the load which moves with constant velocity, are made. In particular, it is established that the influence of the fluid viscosity of the aforementioned quantities becomes more considerable under lower velocities of the moving load. Moreover, it is established that there exists a critical velocity of the moving load under which a resonance type event takes place.     

Algorithms for automatic test procedures of instruments with discrete-analog bar indicators

Translated from Izmeritel'naya Tekhnika, No. 12, pp. 7–10, December, 1989.