A computational modeling on thermodynamic performances of BeX(X = Ag, Au) intermetallics

Abstract

The present work reports thermodynamics of BeX(X = Ag, Au) intermetallics in terms of their unit cell volume, bulk moduli, molar heat capacity at constant volume, Gruneisen parameter, thermal expansion coefficient and Debye temperature using a computational quantum mechanical modeling in the frame work of Density-functional theory (DFT). The thermodynamic parameters were studied under temperature range of 0–1200 K and pressure range of 0–40 GPa. The molar heat capacity at constant volume for the considered intermetallics followed Debye T3 law and Dulong-Petit limit was achieved at certain temperature. Further, to understand the highest modes of vibrations in the materials, Debye temperatures for BeAg and BeAu were estimated as 430 K and 335 K, respectively at 0 K and 0 GPa. Furthermore, the thermal expansion coefficient described the dependence of expansion and contraction of the materials on changing temperature, depicting the strength of atomic bonding. Its high value indicated weak atomic bonding, which led to the low melting temperature in the solids.