First-Principles Prediction of Room-Temperature Ferromagnetic Semiconductor MnS2 via Isovalent Alloying

Although semiconducting ferromagnetism has been experimentally discovered in two-dimensional (2D) crystals, the spin coupling is still quite weak, which leads to a rather low Curie temperature (T-C). Thus, it is quite confused whether the ferromagnetism in semiconductors can survive under room temperature. Here, through isovalent alloying, we propose that the semiconducting ferromagnetism of 2D MnS2 can be significantly enhanced with T-C improved higher than room temperature. Based on first-principles calculations, we systematically studied the properties of original MnS2 and the isovalent alloying systems MnxRe1-xS2. The spin coupling is significantly enhanced by introducing Mn-Re virtual bonds, and the highest T-C of the system reaches 360 K. Besides this, a tensile strain will further enhance the ferromagnetic couplings as well as the uniaxial magnetic anisotropy, which is important for the stabilization of long-range ferromagnetic order in a 2D system. Our results not only broaden the family of 2D ferromagnetic semiconductors but also provide the direct clues to prepare such high-temperature magnetic materials for promising applications in spintronics.