Superconducting atmospheric structure and pressure-induced novel phases of cobalt mononitride

Abstract The study of Cobalt mononitride (CoN) is of significant interest due to its excellent physical and mechanical properties as well as potential applications in magnetic storage and superconductive materials. In this work, we found that the ambient-pressure phase of ZnS-type CoN is superconductive with a superconducting critical temperature of 16.1 K. In addition to the superconductive nature of CoN at ambient pressure, we have also performed structure searches with the aim of identifying high-pressure phases of CoN, as a result, where an orthorhombic phase Pmc21 and a hexagonal phase P63 are found to become energetically more favorable than ZnS-type phase under high pressure. The dynamical and mechanical stabilities of predicted phases have been verified by calculating their phonons and elastic constants, indicating they are likely to be synthesized and recovered to ambient condition. The present results reveal that the CoN compound can be used as hard and superconductive materials, providing a broad prospect for practical applications.