First-principles study of mechanical, thermodynamic, transport and superconducting properties of Sr3SnO

We have performed a comprehensive set of first-principles calculations to study mechanical, thermal, transport and superconducting properties of Sr3SnO, an antiperovskite Dirac-metal oxide. Sr3SnO cubic crystal is found to be elastically stable, anisotropic and brittle in nature. The Debye temperature and bulk modulus are found to decrease with increasing temperature but increase with increasing pressure. However, the specific heats are found to increase due to the increase of temperature. The Gaspari and Gyorffy formalism within the rigid muffin tin approximation is used to calculate the electron phonon coupling constant and hence transition temperature (Tc). The density of states is dominated by Sr-4d and Sn-5p electrons near the Fermi level and the mixing of Sr-4d and Sn-5p causes the topological superconductivity in Sr3SnO. The calculated Tc (8.38 K) is reasonably close to the experimental value (∼5 K).