Ab initio study of structural phase stability and elastic properties of ScSb and YSb under pressure effect

A theoretical studies of structural, elastic and high pressure properties in MSb (M = Sc, Y) are performed, using the full-potential augmented plane wave plus local orbitals method (FP-APW + lo). The equilibrium lattice constant and the bulk modulus agree well with the experiments. The pressures at which these compounds undergo structural phase transition from NaCl (B1) to CsCl (B2) phase were found to be in good agreement with the available experimental data. We have determined the elastic constants C11C11, C12C12 and C44C44 at zero pressure in both B1 and B2 structures, which have not been established neither experimentally nor theoretically. Further, we have also calculated the pressure dependence of the elastic constants.