A tetragonal phase MnB sheet: a stable room temperature ferromagnet with sizable magnetic anisotropy.

Exploring the magnetic properties of two-dimensional (2D) metal boride (MBene) sheets for spin-based electronics is gaining importance for developing electronic devices. Through combined first-principles calculations and Monte Carlo simulations, we present a new tetragonal MnB (tetra-MnB) sheet. The tetra-MnB sheet shows metallic ferromagnetism (2.65 μ per Mn atom) with excellent stability. Moreover, it is demonstrated that the tetra-MnB sheet holds promise for experimental synthesis within an acceptable range from the results of stability tests of tetra-MnB. We also find that the magnetic anisotropy (MAE) of the 2D tetra-MnB sheet is significantly increased under an electric field. The Curie temperature (T) of the tetra-MnB sheet is calculated as 406 K. This 2D tetra-MnB with a high Curie temperature can serve as a promising candidate for future magnetoelectronics applications.