High-pressure elasticity and lattice dynamics of Mg2La from first principles

Abstract: In this study, we present the results of first principles calculations of elastic constants and structural properties of the Mg2La cubic Laves phase (C15) up to ≈150GPa pressure together with vibrational properties at equilibrium geometry. projector augmented wave (PAW) potentials are used with generalized gradient approximation (GGA) scheme of the density functional theory. The linear response technique of the density functional perturbation theory is applied in investigation of the phonon dispersion spectra. The static equation of states of the system has been studied with Vinet formulation. The values of applied pressure have also been obtained from the Vinet formulation of equation of states. The cubic phase of the system remains stable within the studied pressure range. The elastic anisotropy ratio indicates an electronic topological transition (ETT) around ≈100GPa. This situation is also confirmed by electronic band structures. [Copyright &y& Elsevier]