Physical properties of niobium based intermetallics (Nb3B; B = Os, Pt, Au): a DFT based ab-initio study

TL;DR

This study uses density functional theory to analyze the structural, electronic, and bonding properties of Nb3B intermetallics (B=Os, Pt, Au), revealing detailed insights into their electronic structure, bonding nature, and elastic properties.

Contribution

First-principles DFT calculations of Nb3B compounds provide detailed electronic, bonding, and elastic property analysis, including Fermi surface features and charge density distribution, not previously explored.

Findings

Fermi surfaces contain both hole- and electron-like sheets with systematic changes from Os to Au.

Bonding involves a mixture of ionic, covalent, and metallic contributions.

Debye temperatures show systematic variation with B atomic species.

Abstract

Structural, elastic and electronic band structure properties of A-15 type Nb-based intermetallic compounds Nb3B (B = Os, Pt, Au) have been revisited using first principles calculations based on the density functional theory (DFT). All these show excellent agreement with previous reports. More importantly, electronic bonding, charge density distribution and Fermi surface features have been studied in detail for the first time. Vickers hardness of these compounds is also studied. The Fermi surfaces of Nb3B contain both hole- and electron-like sheets, the features of which change systematically as one move from Os to Au. The electronic charge density distribution implies that Nb3Os, Nb3Pt and Nb3Au have a mixture of ionic and covalent bondings with a substantial metallic contribution. The charge transfer between the atomic species in these compounds has been explained via the Mulliken bond population analysis and the Hirshfeld population analysis. The bonding properties show a good correspondence to the electronic band structure derived electronic density of states (DOS) near the Fermi level. Debye temperature of Nb3B (B = Os, Pt, Au) have been estimated from the elastic constants and show a systematic behavior as a function of the B atomic species. We have discussed implications of the results obtained in this study in details in this paper.