Effect of irradiation with reactor neutrons and the temperature of subsequent heat treatment on the structure of InP single crystals

The results of studying the features of the effect of irradiation with fast and full-spectrum reactor neutrons and subsequent heat treatments on the structural characteristics of InP single crystals are reported. It is shown that, in contrast to other III–V semiconductor compounds, the lattice constant decreases in InP as a result of irradiation with neutrons. Fast neutrons make the major contribution to the variation in the lattice constant. The presence of the component of thermal neutrons that give rise to Sn atoms in the material does not bring about any appreciable variation in the lattice constant. Heat treatment of irradiated samples at temperatures as high as 600°C leads to annealing of radiation defects and recovery of the lattice constant; in the samples irradiated with high neutron fluences, the lattice constant becomes even larger than that before irradiation. An analysis of the obtained experimental data made it possible to assume that the decrease in the InP lattice constant as a result of irradiation with neutrons is mainly caused by the introduction of the P_In antisite defects that give rise to an effect similar to that of vacancy-related defects.     

Features of a technique for investigation of partially stabilized zirconia crystals

The structure of partially stabilized zirconia crystals is investigated by X-ray diffractometry and transmission electron microscopy. It is shown that the combination of structural methods allowed one to reveal features of the structure and phase composition of these materials. Partially stabilized zirconia has a complex twin-domain structure. X-ray diffractometry with the use of K _β radiation shows the presence of two phases of the tetragonal modification of zirconia with different tetragonality in all investigated samples independently of the content of the stabilizing impurity. The combination of the locality of transmission microscopy with the integral nature of X-ray diffractometry allowed one to reveal the dependence of the dispersion of twin domains on the concentration of the stabilizing impurity. The use of transmission microscopy with high resolution demonstrates the hierarchy of twinning and the presence of twin domains ～10 nm in width.     

Atomic structure and methods for structural investigations how ingot growth conditions of Bi<Subscript>2</Subscript>Te<Subscript>2.7</Subscript>Se<Subscript>0.3</Subscript> solid solutions influence the physical properties of anisotropy

The properties anisotropy of thermoelectric solid solutions of bismuth chalcogenides are investigated. The ingot texture obtained with the help of zone melting and by the modified Bridgeman method (the procedure for thermoelectric plates growing in a flat cavity) is studied. The texture has been investigated and it is revealed that if the crystallization is performed by the modified Bridgeman method, not only the crystallization rate but also the crystallization cavity embodiment are important for forming the solid structure of thermoelectric material.