Two-step solid-state synthesis of ternary nitride materials

Abstract

Ternary nitrides with strong metal-nitrogen bonds are an emerging class of inorganic materials for use in a variety of optical, electronic, and refractory applications. However at the elevated synthesis temperatures, entropy favors formation of strong dinitrogen triple bonds, which is often counteracted at high reaction pressures, making synthesis process difficult.Here we report on a simple two-step ion-exchange synthesis of MgZrN 2 and Mg 2 NbN 3 with rocksalt-derived structure as well as the MgMoN 2 with layered hexagonal structure, whereas the corresponding one-step reactions lead to decomposition into binaries. Differential Scanning Calorimetry reveals that the first low-temperature reaction step is facilitated at phase transition temperatures of chloride precursors, which promotes the local ternary Mg−TM−N bond formation. Overall, these results demonstrate a low-temperature ambient-pressure approach to synthesize new ternary nitride materials.