Structural, phonon, elastic, thermodynamic and electronic properties of Mg–X (X = La, Nd, Sm) intermetallics: The first principles study

Abstract

We show the results of first-principles calculations of structural, phonon, elastic, thermal and electronic properties of the Mg–X intermetallics in their respective ground state phase and meta-stable phases at equilibrium geometry and the studied pressure range. Phonon dispersion spectra for these compounds were investigated by using the linear response technique. The phonon spectra do not show any abnormality in their respective ground state phase. The respective ground states phases of the studied system remain stable within the studied pressure range. Electronic and thermodynamic properties were derived by analysis of the electronic structures and quasi-harmonic approximation. The mixed bonding character of the Mg–X intermetallics is revealed by Mg–X bonds, and it leads the metallic nature. Most of the contribution originated from X ions d like states at Fermi level compared to that of Mg ion in these intermetallics. In this work, we also predicted the melting temperature of these intermetallics and evaluated the Debye temperature by using elastic constants.