Theoretical examination of superconductivity in the cubic antiperovskite Cr3GaN under pressure

Abstract

We present results of a first-principles investigation of the lattice dynamics and electron-phonon coupling of Cr3GaN under pressure within a linear response approach based on density functional perturbation theory. It is found that stable phonon modes are maintained throughout the Brillouin zone in the pressure range 0-100 GPa. Our results at zero pressure indicate that the material is a conventional electron-phonon superconductor with intermediate level of coupling strength. It is further found that the decrease in the density of states at the Fermi level and the increase of phonon frequencies under pressure are the main causes for a monotonic decrease of the electron-phonon coupling parameter and the superconductor transition temperature. © 2013 AIP Publishing LLC.