Photoelectrical Characteristics of MIS Structures on the Basis of Heteroepitaxial HgCdTe

The voltage dependence of photo-emf in the HgCdTe/SiO ₂ /Si ₃ N ₄ and HgCdTe/AOF MIS structures is experimentally studied. The heteroepitaxial graded-band films Hg _0.78 Cd _0.22 Te were produced on the GaAs substrates by molecular-beam epitaxy. It was found that the type of field dependence of photo-emf is related to the conduction type of the semiconductor used and to the presence of near-surface graded-band layers.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 35–39, February, 2005.     

Electron—Positron annihilation in the narrow-band semiconductor Hg1−xCdxTe

Positron annihilation processes in mercury—cadmium—telluride semiconductor compounds have been studied. Calculations of the positron thermalization time, the bulk annihilation rate, and the positron capture rate for the simplest crystal lattice structural defects have been carried out. The annihilation properties of materials containing growth defects and defects induced by high-energy particles have been determined experimentally. The profiles of vacancy-type defects formed during ion implantation were determined using slow positrons. The positron annihilation data are compared with the results of electrophysical measurements.V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 3–21, October, 1995.     

Stress state of laminar composites

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 25, No. 3, pp. 70–76, March, 1989.     

Recombination of nonequilibrium charge carriers in epitaxial Hg1−x Cdx Te MBE films

We present the results of charge-carrier lifetime measurements in narrow-band Hg_1−xCd_xTe epitaxial structures (x=0.210–0.225) grown by molecular-beam epitaxy (MBE) using pulsed excitation by radiation at various wavelengths. In p-type epitaxial films the carrier lifetime is governed by Shockley-Read recombination at impurity-conduction temperatures. The governing factor for n-type epitaxial films is Auger recombination, with some contribution from other recombination mechanisms (surface and macrodefects). V. D. Kuznetskov Siberian Physicochenical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 96–101, September, 1997.     

Growth of Germanium Quantum Dots on Oxidized Silicon Surface

Russian Physics Journal - Epitaxial growth of germanium quantum dots on an oxidized silicon surface is considered. A kinetic model of the nucleation and growth of three-dimensional islands by the...     

Hybrid membranes based on short side chain perfluorinated sulfonic acid membranes (Inion) and heteropoly acid salts

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Ammine magnesium borohydride complex as a new material for hydrogen storage: structure and properties of Mg(BH4)2.2NH3

The ammonia complex of magnesium borohydride Mg(BH4)2.2NH3 (I), which contains 16.0 wt % hydrogen, is a potentially promising material for hydrogen storage. This complex was synthesized by thermal decomposition of a hexaaammine complex Mg(BH4)2.6NH3 (II), which crystallizes in the cubic space group Fm3 m with unit cell parameter a=10.82(1) A and is isostructural to Mg(NH3) 6Cl2. We solved the structure of I that crystallizes in the orthorhombic space group Pcab with unit cell parameters a=17.4872(4) A, b=9.4132(2) A, c=8.7304(2) A, and Z=8. This structure is built from individual pseudotetrahedral molecules Mg(BH4)2.2NH3 containing one bidentate BH4 group and one tridentate BH4 group that pack into a layered crystal structure mediated by N-H...H-B dihydrogen bonds. Complex I decomposes endothermically starting at 150 degrees C, with a maximum hydrogen release rate at 205 degrees C, which makes it competitive with ammonia borane BH 3NH3 as a hydrogen storage material.