Insight into the physical properties of two niobium based compounds Nb3Be and Nb3Be2 via first principles calculation

Abstract

We investigate the structural, electronic, mechanical and elastic properties of two niobium based intermetallic compounds Nb3Be and Nb3Be2 by using the DFT based theoretical method. A good agreement is found among the structural parameters of both the phases with experimentally evaluated parameters. For both the phases metallic conductivity is observed while Nb3Be phase is more conducting than that of Nb3Be2 phase. Evaluated DOS at Fermi level indicates that Nb3Be2 phase is electrically more stable than Nb3Be phase. For both phases Nb-4d states is mostly responsible for metallic conductivity. The study of total charge density and Mulliken atomic population reveal the existence of covalent, metallic and ionic bonds in both intermetallics. Both the phases are mechanically stable in nature while Nb3Be phase is more ductile than Nb3Be2 phase. The study of Vickers hardness exhibits that Nb3Be2 phase is harder than that of Nb3Be. Both compounds are anisotropic in nature while Nb3Be phase possesses large anisotropic characteristics than that of Nb3Be2 phase. The Debye temperature of both the compounds are also calculated and discussed.