Electron doping induced stable ferromagnetism in two-dimensional GdI3 monolayer

As a two-dimensional material with hollow hexatomic ring structure, Néel-type anti-ferromagnetic (AFM) GdI3 can be used as theoretical model to study the effect of electron doping. Based on first-principles calculations, we find that Fermi surface nesting occurs when more than 1/3 per Gd is doped, resulting in failure obtain stable ferromagnetic (FM) state. More interestingly, appropriate Mg/Ca doping (1/6 Gd) turns half-metallic FM This AFM–FM transition results from transfer doped electrons spatially expanded Gd-5d orbital, which leads coupling local half-full Gd-4f through 5d–4f hybridization. Moreover, shortened Gd–Gd length key formation coupling. Our method provides new insights into obtaining materials AFM materials.