Fe2C monolayer: An intrinsic ferromagnetic MXene

Monolayer Fe2C, a member of MXene group, has been investigated by the first-principles calculations. Fe2C MXene is predicted to be metallic and ferromagnetic. To estimate the strength of magnetic coupling, the Heisenberg model is employed to obtain the magnetic exchange interaction parameters. To understand the mechanism yielding the magnetic ordering, the Stoner's criterion is invoked, and ID(EF)>1 is fulfilled to induce the itinerant ferromagnetic ordering in Fe2C MXene. In addition, the magnetic anisotropy energy for the Fe2C MXene is −22.8 μeV per unit cell, and it has an easy plane for the magnetization, indicating that the magnetic system belongs to the XY model magnets. The Curie temperature from the mean-field approximation is 861 K, which is well above the room temperature. Thus, monolayer Fe2C is an intrinsic ferromagnetic MXene with a high Curie temperature, which is a promising candidate for spintronic applications.