A complete DFT description on structural, electronic, elastic, mechanical and thermodynamic properties of some intermetallic AuX2 (X = Al, Ga, In) compounds

Abstract

The electronic structure, elastic, mechanical and thermodynamic properties of some cubic intermetallic compounds AuX2(X = Al, Ga, In) have been studied within the density functional theory (DFT) using the full potential linearized augmented plane-wave technique (FP-LAPW). The designed values of structural parameters including lattice constant, bulks modulus and ground-states energies are found in good agreement with the available data. The spin included electronic examination presents the metallic nature for all the three compounds with symmetry in spin-up and spin-down states. The elastic properties have been calculated under ambient conditions and have been used to envisage some vital mechanical factors like bulk modulus (B), Young’s modulus (Y), shear modulus (G), Poisson ratio ( $ \nu$ ) and anisotropic factor (A). The calculated results reveal that AuX2(X = Al, Ga, In) compounds establish low elastic anisotropy, low hardness and high ductility. Quasi-harmonic Debye approximation has been used to investigate pressure and temperature dependence of bulk modulus (B), heat capacity (Cv), thermal expansion ( $ \alpha$ , and Debye temperature ( $ \theta_{\rm D}$ . Furthermore, Cv was found to strictly follow the Debye T3-law and Dulong-Petit limit for all the three compounds.