Synthesis of stoichiometric and bulk CrN through a solid-state ion-exchange reaction.

Chromium mononitride (CrN) exhibits interesting magnetic, structural, and electronic properties for technological applications. Experimental reports on these properties are often inconsistent owing to differences in the degree of nonstoichiometry in CrN(x). To date, the preparation of bulk and stoichiometric CrN has been challenging; most products are in the form of a thin film produced by non-equilibrium processes, and are often nonstoichiometric and poorly crystallized. In this work, we formulated a solid-state ion-exchange route for the synthesis of CrN under high pressure. The final CrN product is phase-pure, stoichiometric, and well-crystallized in the bulk form. Near-stoichiometric and well-crystallized CrN can be synthesized using the same route at atmospheric pressure, making massive and industrial-scale production technologically feasible. The successful synthesis of stoichiometric and bulk CrN is expected to open new opportunities in diverse areas of fundamental research.