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 (TC). 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 TC 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 TC 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.