Electronic structure, phase stability and elastic properties of ruthenium based four intermetallic compounds: Ab-initio study

The structural, electronic and elastic properties of four RuX (X = Sc, Ti, V and Zr) intermetallic compounds have been investigated by using density functional theory within full potential linearized augmented plane wave method and using generalized gradient approximations in the scheme of Perdew, Burke and Ernzrhof (PBE), Wu and Cohen (WC) and Perdew et al. (PBEsol) for the exchange correlation potential. The relative phase stability in terms of volume-energy and enthalpy-pressure for these compounds is presented for the first time in three different (B-1, B-2 and B-3) structures. The total energy is computed as a function of volume and fitted to Birch equation of states to find the ground state properties such as lattice constant (a(0)), bulk modulus (B) and its pressure derivative (B'). It is found that the lattice parameters in B-2-phase agree well with the existing experimental and previous theoretical results. The second order elastic constants (SOECs) are also predicted for the above compounds. All the four compounds show ductile behavior. The ductility of these compounds has been analyzed using Pugh's rule. From the plots of electronic density of states (DOS), it can be concluded that these intermetallic compounds are metallic in nature. (C) 2014 Elsevier Ltd. All rights reserved.