Structure of the energy bands in semiconductors of the AIBIIIC2 VI type AgInS2, AgInSe2, AgInTe2

The energy-band structure of the compounds AgInS₂, AgInSe₂, AgInTe₂ is calculated. These compounds are found to have a simple type of conduction band, which consists of several competing maxima lying at different points of the Brillouin zone.     

Laser excited Raman spectra of Gr. VI semiconducting compounds

Raman spectra of hexagonal layer compounds MoS₂, MoSe₂ and MoTe₂ were excited by a HeNe laser (6328Å). All the Raman active long-wave-length phonon frequencies were determined. These are A_1g, E¹_2g, E_1g and E²_g. The frequencies decrease as we pass from sulphur to tellurium and the quasiacoustical mode E²_2g has the lowest frequency. A comparison of the results with infrared spectra shows that the i.r. active mode for E ⊥ C is degenerate with one of the Raman active modes in the basal plane for all the compounds.     

Atomic chains and lattice vibration characteristics in A2 IIIB3 VI compounds with tetrahedral coordination of atoms

On the basis of the presence of atomic chains in A₂ ^IIIB₃ ^VI compounds having zincblende defect structure, a linear-chain model is used to calculate the lattice vibration frequencies. The agreement of the calculated and experimental frequencies is an indication of the applicability of the model and enables one to determine the motion of various atoms during the corresponding vibrations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 83–88, April, 1977.     

On the lattice defects in Nasicon compounds

Summary  Samples of Nasicon compounds (Na super ionic conductor) with different silicon and phosphorus contents were investigated by performing radioluminescence experiments. In all samples examined, the Frenkel pairs, originated by the displacements of sodium ions in lacunar sites, were found to be the dominant defects. Some useful information on sodium ion mobility was obtained from the analysis of radioluminescence spectra.     

On some kinetic phenomena in ordered and disordered substances

A new temperature behaviour of nuclear magnetization is predicted. The relaxation theory in disordered ferromagnets is presented. The scattering of quasiparticles on two-level systems is described. A nonlinear susceptibility of ferromagnets is calculated.     

The theory of infrared dispersion of light in crystals with chalcopyrite lattice

The low-frequency dielectric tensor is calculated for A^IIB^IVC ₂ ^V and A^IB^IIIC ₂ ^VI crystals in terms of the long-wave frequencies of lattice vibrations, corresponding to various orientations of the wave vector. The qualitative shape of the spectrum of mechanical polaritons is obtained. The coefficient of light reflection is calculated as a function of the frequency and direction of propagation for a CdGeP₂ crystal.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 39–43, June, 1978.     

Lattice dynamics and chemical binding in semiconducting compounds II-IV-V2

Russian Physics Journal -     

The role of some physical parameters on the magnetic susceptibility of group II–VI semiconducting compounds

The magnetic susceptibility of II–VI compounds is correlated with certain physical paitameters, such as atomic numbers, band-gap energy, refractive index and lattice parameter. A plausible explanation is given to some of these correlations in the light of recent theories.     

二维Frenkel-Kontorova模型中六角对称结构的摩擦现象

基于二维 Frenkel-Kontorova 模型, 运用分子动力学模拟方法, 研究了具有六角对称结构的系统从 locked 态到 sliding 态的相变, 并数值分析了上层原子采用六角对称结构时, 系统的不同参数对静摩擦力F_s和动摩擦力F_c的影响. 关键词： 二维 Frenkel-Kontorova 模型 超润滑 分子动力学 摩擦     

The luminescence of II–VI compounds with blende type structure under high excitation

The luminescence of ZnSe is investigated as a function of excitation intensity for temperatures between 5 K and 300 K. At low excitation we observe emission due to free and bound excitons and due to donor-acceptor pair recombination. At higher excitation, the emission is dominated by inelastic exciton-exciton and exciton-free carrier scattering at lower and higher temperatures, respectively. A “M-band” observed in ZnSe and ZnTe is tentatively ascribed to a biexciton decay. The biexciton binding energies are 2±1 meV for ZnSe and 1,5±1 meV for ZnTe.     

On the valence and lattice parameter in cerium intermetallic compounds

Experimental data concerning valence and lattice parameter in cerium intermetallic compounds are discussed using the concepts of electronic charge screening and charge transfer between the rare earth and the transition element.     

Bond ionicity and susceptibility in aIbIIIc2VI compounds

The electronic susceptibilities, energy gaps and the bond ionicities of some A^IB^IIIC₂^VI chal-copyrite compounds have been calculated from their plasmon energy. The effect of delocalization of noble metal d-electrons has been taken into account while calculating these parameters in the case of the A^I-C^VI bond. A comparison is made between the present results and the results of previous calculations.     

Energy band structures of the chalcopyrite lattice semiconductors CuAlS2, CuAlSe2, CuInS2, and CuInSe2

The pseudopotential method is used to calculate the energy band structures of four -type semiconductors including the effect of the displacement of anions from face-centered sites in the sublattices. It was established that CuAlSe₂, CuInS₂, and CuInSe₂ are direct gap semiconductors and that CuAlS₂ has a pseudodirect energy gap. Experimental data derived from studies of the optical properties of these crystals in the U V region are also discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 7–12, June, 1976.