Vibrational, mechanical, electronic and thermodynamic properties of rhenium-based perovskites XReO3(X = Li, Be) by an ab-initio computation

Abstract

First-principles density functional theory calculations were used to determine the structural, elastic, electronic and thermodynamic properties of XReO3(X = Li, Be) cubic perovskite compounds in the framework of DFT. Our obtained results of lattice constant (a) related to XReO3(X = Li, Be) are found to be 3.857 Å, and 3.89 Å, respectively. From the band-structure computation, the XReO3(X = Li, Be) compounds show their metallic character. Elastic characteristics were investigated by measuring the Poisson's ratio (v), Young's modulus (Y), isotropic shear modulus (G), and anisotropy factor (A). The computed values of the elastic constants such as C11, C12 and C44 and Born-Huang stability criterion suggest their mechanical stability whereas the computed values of the anisotropic constant ‘A’ suggest its anisotropic character. The Cauchy pressure as well as B/G ratio calculations, the ductility behaviour of the XReO3(X = Li, Be) compounds is confirmed. Finally, the Helmholtz free energy (F), entropy (S), and heat capacity (CV) were computed and analysed for temperatures ranging from 0 to 1000 K. Our results show that the XReO3(X = Li, Be) compounds could be used in the near future to make new and useful devices.