Density-Functional-Theory Study of Cohesive, Structural and Electronic Properties of Ni-Sb Intermetallic Phases

Abstract

This work has its roots in a long-term theoretical research line aimed at developing a complete database with structural, thermodynamic, cohesive and elastic properties of the intermetallic compounds (ICs) of the type MeaXb where Me = Cu, Ni and X = In, Sn and Sb. The paper reports the results of an ab initio study of various phases occurring in the Ni-Sb phase diagram, viz., the low-temperature Ni3Sb (orthorhombic oP8), the high-temperature Ni3Sb (cubic cF16), Ni5Sb2 (monoclinic mC28), NiSb (hexagonal hP4) and the NiSb2 (orthorhombic oP6) compounds. The molar volume, bulk modulus and its pressure derivative, the electronic density of states (DOS) and the energy of formation from the elements of these compounds are calculated ab initio using the relativistic projected augmented wave (PAW) method implemented in the VASP code. The Local Density Approximation of Ceperley and Alder and the Generalized Gradient Approximation due to Perdew and Wang are adopted to treat the exchange and correlation energies. Detailed comparisons between the current and previously reported theoretical and experimental values are reported.