First-principles study on the electric field manipulation of the magnetic property and the electronic structures for monolayer Fe2C MXene

Abstract

In this research, we investigate the magnetic properties, electronic structures, magnetic anisotropy and Curie temperature (TC) of monolayer Fe2C by first-principles calculation. The calculation results show that the ground state of Fe2C should be ferromagnetic (FM) state. Introducing a vertical electric field (E⊥) to monolayer Fe2C, we find that the Dirac points can be opened or formed in FM state. For A-AFM state, the transitions of electronic structures appear with the variation of the electric field. We also calculate the magnetic anisotropy energy (MAE) and find that z-axis is the magnetic hard axis, xy-plane is the magnetic easy plane. The electric field can tune the magnetic easy direction. TC of monolayer Fe2C is estimated to be 662 K by the mean-field approximation method. As the electric field increases, the exchange parameters decrease, which results in the reduction of TC. When E⊥ reaches 0.35 V/Å, T≈C300 K. Therefore, this study provides a good theoretical guide for reducing the magnetic materials with high TC to room temperature.