Scalable Synthesis of Ultrathin Mn₃N₂ Exhibiting Room‐Temperature Antiferromagnetism

Abstract Ultrathin and 2D magnetic materials have attracted a great deal of attention recently due to their potential applications in spintronics. Only a handful of stable ultrathin magnetic materials have been reported, but their high‐yield synthesis remains a challenge. Transition metal (e.g., manganese) nitrides are attractive candidates for spintronics due to their predicted high magnetic transition temperatures. Here, a lattice matching synthesis of ultrathin Mn 3 N 2 is employed. Taking advantage of the lattice match between a KCl salt template and Mn 3 N 2 , this method yields the first ultrathin magnetic metal nitride via a solution‐based route. Mn 3 N 2 flakes show intrinsic magnetic behavior even at 300 K, enabling potential room‐temperature applications. This synthesis procedure offers an approach to the discovery of other ultrathin or 2D metal nitrides.