Study of structural, elastic, electronics, optical and thermodynamic properties of Hf2PbC under pressure by ab-initio method

Abstract

Different physical properties such as structural, mechanical, electronic, optical and thermodynamic of compound Hf2PbC have been investigated under pressure (0–40 GPa) using first principles method. The variation of elastic constants Cij, bulk modulus B, shear modulus G, Young’s modulus E, anisotropy factor A and Poisson’s ratio ν with pressure are calculated and discussed in details. The increase of elastic constants with pressure ensured that the compound Hf2PbC becomes more resistant to shear deformation with pressure. The linear response of bulk modulus and Young’s modulus with pressure indicates the increase of hardness of Hf2PbC with increasing pressure. The Pugh’s ratio from 0 to 30 GPa ensured the brittle nature of Hf2PbC but ductile nature appeared at 40 GPa where the phase transition may occur. The electrically conductive behavior is confirmed from the band structure and DOS calculations. The existences of covalent and ionic bonds are ensured by the Mulliken population analysis. Optical properties such as absorption, refractive index, loss function, dielectric function and reflectivity are also analyzed under pressure. We observed the increase of optical conductivity and absorption and decrease of reflectivity and loss function with increasing pressure. The Debye temperature is calculated using the elastic constants and it increases with pressure. Furthermore, the minimum thermal conductivity and the melting temperature are investigated and these values are also increased with pressure.