Strain- and Carrier-Engineered Electromagnetic Properties in Transition-Metal Chalcogenide Monolayers: Implications for Nanoscale Spintronic Devices

Magnetic semiconductors, which are characterized by strong magnetic coupling and semiconducting features, have the potential to be applied in spintronic devices. Here, a family of TM 3 X 5 (TM = V, Fe, Co, Ni; X = O, S, Se) monolayers were predicted to be robust magnetic semiconductors based on first-principles calculations. Our findings show that the V 3 Se 5 monolayer exhibits ferromagnetic (FM) semiconductor character, while Fe 3 S 5, Co 3 O 5, and Ni 3 O 5 monolayers are found to be antiferromagnetic (AFM) semiconductors. Among them, the FM order in the V 3 Se 5 monolayer is ultraly stable with a high Curie temperature of 500 K, which can be enhanced to 900 K under 2% tensile strain. Moreover, the electronic and magnetic properties of these TM 3 X 5 monolayers are sensitive to carrier doping. The Ni 3 O 5 monolayer can be transformed to an AFM half-metal or an AFM bipolar magnetic semiconductor under electron or hole doping, respectively. Such properties endow TM 3 X 5 monolayers with tremendous potential for practical applications in the realm of nanoscale spintronic devices.