First principles study on structural, electronic and elastic properties of AgX and AuX (X = Mg, Sc, Zn and Cd) intermetallic compounds

Abstract

The electronic, elastic and mechanical properties of eight binary B2 – type intermetallic compounds of Ag and Au (AgX and AuX, X=Mg, Sc, Zn and Cd) have been studied systematically using first principles density functional theory within generalized gradient approximation. Ground state properties such as lattice constant (a0), bulk modulus (B), its pressure derivative (B′) and elastic constants are calculated. The present results are in good agreement with the experimental and other available theoretical results. Poisson’s ratio (σ), Young’s moduli (E), shear moduli (GH) and the ratio of elastic anisotropy factor (A) are also estimated. Ductility for these compounds is further analysed by calculating the ratio of B/GH and Cauchy pressure (C12–C44). Amongst all the intermetallics AuZn is found to be most ductile due to the presence of strong metallic bonding, and AgZn is least ductile in all the Au and Ag intermetallic compounds.