Predication of Thermal Conductivity of Mg2X (X = Ge and Sn) by Molecular Dynamics

Abstract

Molecular dynamics (MD) simulations of elastic and thermal properties of Mg2X (X = Ge and Sn) based on anti-fluorite structure (CaF2) at temperature range 300−700 K were presented. The MD simulation in this study involving the Morse−type potential functions, and the Busing–Ida potential to determine the interatomic interaction among cluster atoms size 4×4×4 unit cells of 768 atoms {512−Mg1.2+, 256−(Ge, Sn)2.4−}. The potential parameter functions of the cluster atoms were indicated by random numerical method and fit lattice parameter from the experimental data obtained at room temperature. The calculation of lattice parameter, pressure, temperature and energy contributes to evaluation of the elastic properties. The results showed that Mg2Ge had better elasticity than Mg2Sn. On the other hand, Mg2Sn had less thermal conductivity than Mg2Ge. Since thermal conductivity decreases with increasing temperature, the interesting feature of thermal conductivity is particulary useful to enhance thermoelectric performance of materials.