Prediction of superconductivity of $3d$ transition-metal based antiperovskites via magnetic phase diagram

Abstract

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.

11 pages, 15 figures