A comprehensive study of the thermophysical and optoelectronic properties of Nb2P5 via ab-initio technique

Abstract

Binary metallic phosphide, Nb2P5, belongs to important class of materials from the stand point of engineering applications. Quite surprisingly, a large number of physical properties of Nb2P5, including elastic properties and their anisotropy, acoustic, thermophysical, bonding characteristics, and optoelectronic properties have not been investigated in any detail yet. In the present work we have explored all these properties extensively for the first time employing density functional theory based first-principles calculations. Nb2P5 is found to be a mechanically stable, elastically anisotropic compound with weak brittle character. The bondings among the atoms are dominated by covalent and ionic contributions with small signature of metallic feature. The compound possesses high level of machinability. Nb2P5 is a moderately hard compound. Electronic band structure calculations reveal metallic conduction with a large electronic density of states at the Fermi level. Calculated values of different thermal properties indicate that Nb2P5 has the potential to be used as a thermal barrier coating material. The energy dependent optical parameters show close agreement with the underlying electronic band structure. The optical absorption and reflectivity spectra and the static index of refraction of Nb2P5 disclose that the compound has potential to be used in optoelectronic applications. Unlike notable anisotropy in elastic and mechanical properties, the optical constants spectra are found to be largely isotropic.