Pressure induced structural phase transition and elastic properties in BSb, AlSb, GaSb and InSb compounds

By formulating an effective interionic interaction potential that incorporates the long-range Coulomb, the covalency effects, the charge transfer caused by the deformation of the electron shells of the overlapping ions, the Hafemeister and Flygare type short-range overlap repulsion extended upto the second neighbour ions and the van der Waals (vdW) interaction, the pressure dependent elastic and thermodynamical properties of the III–V antimonide semiconductors as YSb (Y=B, Al, Ga, and In) are investigated. Estimated values of phase transition pressure of YSb antimonides are consistent with the available data on the phase transition pressures. The ratio RS/B of S (Voigt averaged shear modulus) over B (bulk modulus), elastic wave velocity, average wave velocity and Debye temperature as functions of pressure is calculated. From the ratio RS/B it is inferred that YSb (Y=Al, Ga, and In) are ductile and BSb is brittle in zinc blende (B3) phase. To our knowledge this is the first quantitative theoretical prediction of the ductile (brittle) nature of YSb antimonides and still awaits experimental confirmations.