First-principles predictions of the structural, dynamical, mechanical and thermal properties of MoGe2, Mo3Ge and Mo5Ge3

Abstract

We have systematically investigated the structural, dynamical, elastic, and thermal properties of the C11b (tetragonal, space group I4/mmm) and C23 (orthorhombic, space group Pnma) for MoGe2 compound, A15 (cubic, space group Pm-3n) for Mo3Ge, D8m (tetragonal, space group I4/mcm) for Mo5Ge3. The simulated lattice constants exhibit strong agreement with both experimental and theoretical data. The results show that all the compounds have mechanical stability and dynamic stability. The anisotropy of some mechanical moduli was studied using several elastic anisotropy indexes and directional dependence of linear compressibility, Young's modulus, shear modulus and Poisson's ratio. At last, the thermal properties of MoGe2-C11b, MoGe2-C23, Mo3Ge-A15 and Mo5Ge3-D8m were studied and evaluated in detail.