A comprehensive DFT based insights into the physical properties of tetragonal superconducting Mo5PB2

Abstract

Tetragonal Mo5PB2, a recently discovered superconductor, is an extension of transition metal binaries with general formula T5M3. A large number of physical properties of Mo5PB2, including elastic properties and their anisotropy, acoustic behavior, electronic (charge density distribution, electron density difference), thermophysical, bonding characteristics, and optical properties have not been carried out at all till date. In this work, all these properties have been studied in details for the first time employing density functional theory based first-principles method. Mo5PB2 is found to be a mechanically stable, elastically anisotropic compound with ductile character. Chemical bonding characteristics are understood from electronic energy density of states, electron density distribution, elastic properties and Mulliken and Hirshfeld bond population analyses. Mo5PB2 has a combination of ionic, metallic, and covalent bondings. Mo5PB2 possesses high level of machinability. Large electronic density of states at the Fermi level, N(EF), reveals its metallic character. High value of N(EF) facilates superconductivity. Calculated values of different thermal parameters of Mo5PB2 are closely related to the elastic moduli and constants. Energy dependent optical parameters show close agreement to the underlying electronic band structure. The optical absorption and reflectivity spectra and the low energy index of refraction of Mo5PB2 disclose its promise to be used in the optoelectronic device sector. Unlike the notable anisotropy found in elastic properties and minimum thermal conductivity, the optical parameters are found to be almost isotropic with respect to the polarization direction of the electric field.