Prediction of superconductivity of $3d$ 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${}_3$ by density function theory. Based on the Stoner criterion, we drew the magnetic phase diagram of carbon-based antiperovskites ACM${}_3$. In the phase diagram, compounds with non-magnetic ground state but locating near the ferromagnetic boundary are suggested to yield sizeable electron-phonon coupling and behave superconductivity. To approve this deduction, we systematically calculated the phonon spectra and electron-phonon coupling of a series of Cr-based antiperovskites ACCr${}_3$ and ANCr${}_3$. The results show that AlCCr${}_3$, GaCCr${}_3$, and ZnNCr${}_3$ could be moderate coupling BCS superconductors. The influence of spin fluctuation on superconductivity are discussed. Furthermore, other potential superconducting AXM${}_3$ including some new Co-base and Fe-based antiperovskite superconductors are predicted from the magnetic phase diagram.