Compositional dependence of the elastic constants and the Poisson ratio of GaxIn1−xSb

The pseudopotential method within the virtual crystal approximation combined with the Harrison bond-orbital model were used to determine all three elastic constants, and hence Poisson's ratio of Ga_xIn_1−xSb semiconductor alloys. Our results for parent compounds are compared to experiment and other theoretical calculations and showed generally good agreement. The effect of compositional disorder on the studied quantities has been examined. We found an important bowing in all elastic constants and bulk modulus versus Ga content. The Poisson ratio was found to be independent of alloy composition x.