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

Abstract

Structural, elastic and electronic band structure properties of A-15 type Nb-based intermetallic compounds Nb 3 B (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 Nb 3 B contain both holeand electron-like sheets, the features of which change systematically as one move from Os to Au. The electronic charge density distribution implies that Nb 3 Os, Nb 3 Pt and Nb 3 Au 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 Nb 3 B (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.

Structural, elastic, electronic, bonding, and optical properties of topological CaSn3 semimetal

“…HPA shows somewhat opposite result compared to the Mulliken charge. That has been also found for other cases [77]. Hirshfeld analysis shows atomic charge of Ca and Sn is -0.03 and +0.01 electronic charge, respectively.…”

An ab-initio study on structural, elastic, electronic, bonding, thermal, and optical properties of topological Weyl semimetal TaX (X = P, As)

“…The overlap population of electrons between atoms is a measurement of the strength of the covalent bond between atoms and the strength of the bond per the unit volume. The positive ( +) and negative (-) values of overlap population indicate the presence of bonding-type and anti-bonding-type interactions between the atoms, respectively 119 , 120 . The overlap population close to zero indicates that there is no significant interaction between the electronic populations of the two bonding atoms.…”

Ab initio approach to the elastic, electronic, and optical properties of MoTe2 topological Weyl semimetal

“…In this investigation we have concentrated on the bulk electronic, optical and mechanical properties of orthorhombic MoTe 2 . Variety of prior studies on diverse class of materials showed that [26][27][28][29][30], as far as optimization of the cell structure, bulk elastic constants, bonding and bulk optical properties are concerned, SOC only has a minimal effect. Within the bulk electronic band structure, SOC mainly reveals itself in split bands with splitting energy of the order of tens of meV.…”

“…For an isotropic solid both the Young's modulus and Poisson's ratio are related to the bulk modulus and shear modulus. Compared to many other binary and ternary metallic compounds [26,[38][39][40][41][42], the elastic moduli of MoTe 2 are small, indicating its soft nature. Since B > G, the mechanical failure in MoTe 2 can be controlled by the applied shear component.…”