Theoretical calculations of elastic, mechanical and thermal properties of REPt3 (RE = Sc, Y and Lu) intermetallic compounds based on DFT

Abstract

The elastic, mechanical and thermal properties of isostructural and isoelectronic nonmagnetic REPt3 (RE = Sc, Y and Lu) intermetallic compounds, which crystallize in AuCu3-type structure, are studied using first principles density functional theory based on full potential linearized augmented plane wave method. The calculations are carried out within PBE-GGA, WC-GGA and PBE-sol GGA for the exchange correlation potential. Our calculated ground state properties such as lattice constant (ao), bulk modulus (B) and its pressure derivative (B′) are in good agreement with the available experimental and other theoretical results. We first time predict the elastic constants for these compounds using GGA approximations. All the compounds are found to be ductile in nature in accordance with Pugh’s criteria. The computed electronic band structures show metallic character of these compounds. The charge density plot and density of states of these compounds reveals that the chemical bond between RE and Pt is mainly ionic. The elastic properties including Poisson’s ratio (σ), Young’s modulus (E), shear modulus (GH) and anisotropy factor (A) are also determined using the Voigt–Reuss–Hill averaging scheme. The average sound velocities (vm), density (ρ) and Debye temperature (θD) of these REPt3 compounds are also estimated from the elastic constants. We first time report the variation of elastic constants, elastic moduli, sound velocities and Debye temperatures of these compounds as a function of pressure.