Investigation of the structural properties of GaAs layers grown by molecular-beam epitaxy at low temperatures

The results of an investigation of the structural perfection of GaAs epitaxial films grown by molecular-beam epitaxy at low growth temperatures (240–300 °C) and various As/Ga flux ratios (from 3 to 13) are presented. Diffraction reflection curves display characteristic features for the samples before and after annealing in the temperature range from 300 to 800 °C. Hypotheses which account for these features are advanced. The range of variation of the arsenic/gallium flux ratio, in which low-temperature growth takes place under nearly stoichiometric conditions, is established. Fiz. Tekh. Poluprovodn. 31, 1168–1170 (October 1997)     

Electrical properties of silicon schottky diodes containing metal films of various compositions

Au _x Ti_{100 ? x} /n-Si Schottky diodes are fabricated and studied; in addition, the electrical properties of diodes containing metal films with varying composition (x = 0, 14, 30, 38, 60, 80, and 100) are also studied. Using X-ray phase analysis, it is established that the film of Au₃₈Ti₆₂ composition has the amorphous structure, while the remaining films Au _x Ti_{100 ? x} possess the polycrystalline structure. The main parameters of the Schottky diodes are determined in relation to the composition and structure of the metal films. As a result, it is shown that the electrical properties of Au _x Ti_{100 ? x} /n-Si Schottky diodes are related to variations in the composition and structure of metal films.     

Thermophysical properties of polyvalent metals and their alloys in the solid and liquid states

Resistivity, thermal conductivity, and ultrasound velocity for the metals of the third group, namely, gallium, indium, and thallium are given in a temperature range from 300 to 1000°K as well as resistivity and thermal conductivity of indium-thallium and thallium-tin alloy systems in wide temperature and concentration ranges.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 38, No. 4, pp. 614–620, April, 1980.     

An acousto-optical converter of videosignal temporal scale

In this paper we discuss an operation of the acousto-optic videosignal temporal scale converter, which can operate in temporal compression mode and also in temporal expansion.     

Effect of a phase transition on the electron energy spectrum in Ag<Subscript>2</Subscript>S

Temperature dependences of electrical conductivity σ, Hall coefficient R, and thermopower α₀ in Ag₂S are reported. It is established that at T ≈ 435 ± 5 K, all kinetic parameters vary drastically, which is associated with a change in parameters of the conduction band. It is shown that the dispersion law of electron energy in β-Ag₂S corresponds to the Kane model.     

A Study of (In,Ga,Al)As/GaAs Quantum-Dot Heterostructures by X-ray Diffraction and Total Reflection

The structure of (In,Ga,Al)As/GaAs stacks with one to three layers of self-assembled InAs quantum dots is studied by high-resolution x-ray diffractometry and x-ray reflectometry. It is shown that the quantum dots are almost pyramidal in shape. It is found that (i) a first InAs layer, 2.7 ML thick, is invariably produced with a faceted surface and (ii) vertical coupling of quantum dots and superlattice formation do occur (with three quantum-dot layers). It is demonstrated that combining the two methods provides researchers with more reliable structural data.     

Computer molecular-dynamics simulation of the structure of crystal nanomaterials

The molecular-dynamics simulation of crystal system of silicon carbide at various temperatures has been performed using methods and programs of computer molecular design. Graphs of radial-distribution functions have been obtained for Si-C pairs of atoms, as well as the configurations of atoms in crystal systems at various temperatures. The dependence of the melting point of the SiC crystal system vs. the characteristics of the initial crystal structure to the approximation of the given Tersoff potential and molecular assembly has been studied at the constant number of particles, pressure, and temperature.     

Acoustophotovoltaic effect in TlIn<Subscript>0.98</Subscript>Gd<Subscript>0.02</Subscript>Se<Subscript>2</Subscript> single crystals

An acoustophotovoltaic effect in TlIn_0.98Gd_0.02Se₂ single crystals has been detected and investigated.