Prediction of Superconductivity in 3d Transition-Metal Based Antiperovskites via Magnetic Phase Diagram

We theoretically studied the electronic structure, magnetic properties, and lattice dynamics of a series of 3d transition-metal antiperovskite compounds AXM sub(3) by density function theory. Based on the Stoner criterion, we drew the magnetic phase diagram of carbon-based antiperovskites ACM sub(3). In the phase diagram, compounds with non-magnetic ground state but locating near the ferromagnetic boundary are suggested to have high N(EF) that may cause sizeable electron-phonon coupling and make the compounds superconducting. To approve this deduction, we systematically calculated the phonon spectra and electron-phonon coupling of a series of Cr-based antiperovskites ACCr sub(3) and ANCr sub(3). The results show that AlCCr sub(3), GaCCr sub(3), and ZnNCr sub(3) could be moderate coupling BCS superconductors. The influence of spin fluctuation on superconductivity are discussed. Furthermore, other potential superconducting AXM3 including some new Co- and Fe-based antiperovskite superconductors are predicted from the magnetic phase diagram.