The mechanical, dynamical, thermodynamical properties and elastic anisotropies of cubic YbAu compound under pressure

Abstract

The structural, elastic, vibrational, electronic and thermodynamic properties of thermodynamically important YbAu in B2 structure under pressure have been investigated by performing first principles method using DFT. The calculated lattice parameter and equilibrium volume are in good agreement with the experimental values. Zero pressure elastic constants and pressure-dependent elastic constants are positive up to 30 GPa. The resulting elastic constants are stable mechanically as they meet the Born stability condition, which makes the YbAu compound stable in nature. B/G ratio shows that the YbAu has a brittle nature while Poisson's ratio (nu) values show that an ionic bond nature. The presented phonon dispersion curves and one-phonon DOS also confirms that this compound is stable dynamically. The electronic structure and metallic nature have been analysed quanti-tatively from band structure and density of states. To better illustrate the nature of bonding and charge transfer, we have studied the charge density plots and mulliken charge analysis. Also, the thermodynamic properties have been investigated under temperature and high pressure. The pressure effects on the volume of YbAu are found to be greater than the temperature effects.