An analysis of structural phase transition and allied properties of cubic ReN and MoN compounds

The present work aims at the study of structural, elastic, electronic, and thermodynamic properties of transition metal nitrides: ReN and MoN in the zinc-blende (B3) phase. The plane wave pseudopotential and norm-conserving pseudopotential have been applied in Quantum-Espresso code based on density-functional theory (DFT). The results show a first-order phase transition from B3 to B1 (rock-salt) structure at 42 GPa and 2.5 GPa for ReN and MoN respectively. The elastic behaviors of these compounds are also unfolded in this work. The brittleness of the ReN and ductility of MoN is identified with the help of Pugh's index and Poisson's ratio. The strong anisotropic behaviors of both compounds are detected under the influence of pressure. The electronic and bonding features of proposed compounds are evaluated by means of band structures, the density of states (DOS), Fermi surface, and charge density plots. The obtained results forecast the metallic behavior and ionic bonding of ReN and MoN in both phases: B3 and B1. Additionally, various thermodynamic properties are also investigated under high pressures and temperatures (from 0 to 2000 K). Conceivably, these properties are reported for the first time in the B3 structure of these compounds and will be useful for many applications in modern technologies as well.

Automated summary

This study aims to investigate the structural, elastic, electronic, and thermodynamic properties of ReN and MoN in the zinc-blende phase, using density-functional theory. The results reveal a first-order phase transition from B3 to B1 structure for ReN at 42 GPa and for MoN at 2.5 GPa, as well as identifying the brittleness of ReN and ductility of MoN. Electronic and bonding properties were evaluated through band structures, density of states, Fermi surface, and charge density plots, while various thermodynamic properties were explored under high pressures and temperatures.