Structural, electronic, elastic and thermal properties of some transition metal CuX (X = Sc and Pd) intermetallics: A FP-LAPW study

A systematic theoretical study using ab initio density functional theory (DFT) based on full potential linearized augmented plane wave (FP-LAPW) method has been performed for the investigation of structural, electronic, thermal and elastic properties of AB-type non magnetic intermetallic compounds. The CuX compounds (X = Sc and Pd) belong to cubic cesium chloride (B2-type, Pm3 m, space group, 221) structure. The exchange correlation energy is described in the three PBE-GGA, WC-GGA and PBEsol-GGA approximations. We have calculated the ground state properties such as lattice constant (a0), bulk modulus (B) and pressure derivative of bulk modulus (B′). The three independent elastic constants (C11, C12 and C44) are also reported. The Debye temperature is estimated from the average sound velocity. Our results are in good agreement with the experimental and previously presented other theoretical data. From electronic band structure (BS) and density of states (DOS), it can be revealed that these intermetallic compounds are metallic in nature. The mechanical properties predicted from the calculated values of elastic constants have also been reported. We have first time predicted the behaviour of elastic constants with pressure. The variation of elastic moduli, sound wave velocities and Debye temperature with pressure are also reported.