Regulating Phase Transition from Metal to Half-Metal and Magnetic Anisotropy in ScX (X = Cl, Br, I) Monolayers via Carrier Doping

Two-dimensional ferromagnetic (FM) materials are vital to develop novel spintronic devices for next-generation information technology. Here, a series of ScX (X = Cl, Br, I) monolayers are predicted, exhibiting that the halogens have a significant impact on the magnetic properties of ScX. Although all the ScX monolayers show a metallic state, the ScCl favors out-of-plane magnetic anisotropy. Both ScBr and ScI monolayers prefer in-plane magnetization. The Curie temperature of ScCl is calculated to be 95 K by Monte Carlo simulations. The Berezinskii-Kosterlitz-Thouless transition temperatures are estimated to be around 587 and 779 K for ScBr and ScI, respectively. Intriguingly, hole and electron doping can effectively modify the magnetic easy axis of ScX between the in-plane and out-of-plane directions. Moreover, a phase transition from metal to half-metal appears in the ScX monolayers by hole doping. Our findings provide a promising platform for developing miniaturized electronic devices.