Equation of state for α-phase GeSn solid solution

Abstract

The equation of state of α-phase solid solution for the GeSn system is studied using the electronic theory based on pseudo-potentials and the virtual crystal approximation. The calculated results of the pressure-volume relation for the α-phase Ge 1− x Sn x solid solution are not monotonic as a function of atomic fraction x, and show a softening of the crystal under compression contrary to those for pure β-Sn. The influence of Sn solubility in Ge on the pressure-induced α− β phase transition i calculated. In the region of x<0.2, where the formation of an α-phase Ge 1− x Sn x solid solution was predicted under pressure, the volume discontinuity ΔΩ solid solution was predicted under pressure, the volume P t remains to be almost, constant, and the latent heat of transition ΔE increases slightly with Sn solubility in Ge.