First-principle study of the structural, mechanical, electronic and thermodynamic properties of intermetallic compounds: Pd3M (M = Sc, Y)

摘要

The mechanical, electronic and thermodynamic properties of Pd3M (M = Sc, Y) compounds have been investigated using the Full Potential Linearized Augmented Plane Wave (FP-LAPW) formalism. The generalized gradient approximation (GGA) is used to treat the exchange{correlation terms. The calculated formation enthalpies and the cohesive energies reveal that the L1(2) structure is more stable than the D0(24) one. The obtained lattice parameters and bulk modulus calculations conform well to the available experimental and theoretical results. The elastic and mechanical properties are analyzed and results show that both compounds are ductile in nature. The Debye temperature and melting temperature are also estimated and are in a good agreement with experimental findings. The total and partial densities of states are determined for L1(2) and D0(24) structures. The density of states at the Fermi level, N(E-F), indicates electronic stability for both compounds. The presence of the pseudo-gap near the Fermi level is suggestive of formation of directional covalent bonding. The number of bonding electrons per atom n(b) and the electronic specific heat coefficient gamma are also determined. The quasi-harmonic Debye model has been used to explore the temperature and pressure effects on the thermodynamic properties for both compounds.