Electrical Transport Properties of Ga(AsxSb1−x) and (GaxIn1−x)Sb Alloys under Hydrostatic Pressure

Abstract

Homogeneous polycrystalline n type samples of the alloys Ga(AsxSb1−x) and (GaxIn1−x)Sb have been prepared from a stoichiometric melt by directional freezing methods. Room temperature measurements of electrical conductivity and Hall coefficient as a function of hydrostatic pressure up to 12 kbars have been made on samples of different composition by means of the van der Pauw technique, all specimens used in the measurements being carefully selected to avoid the presence of grain boundary effects. The experimental curves of conductivity and Hall coefficient as a function of pressure have been fitted to a two conduction band model with various band parameters taken as adjustable. The curves thus fitted give consistent values of E12, the energy separation of the two bands, as a function of x. For (GaxIn1−x)Sb, the E12 values are in good agreement with those obtained previously from measurements as a function of temperature, no previous values having been published for Ga(AsxSb1−x). Approximate values for the coupling coefficient D12 of the alloys are also obtained.