High Curie Temperature Ferromagnetic Semiconductor: Bimetal Transition Iodide V2Cr2I9
Abstract
Bimetal transition iodides in two-dimensional scale provide an interesting idea to combine a set of single-transition-metal ferromagnetic semiconductors together. Motivated by structural engineering on bilayer CrI3 to tune its magnetism and works that realize ideal properties by stacking van der Waals transitional metal dichalcogenides in a certain order. Here we stack monolayer VI3 onto monolayer CrI3 with a middle-layer I atoms discarded to construct monolayer V2Cr2I9. Based on this crystal model, the stable and metastable phases are determined among 7 possible phases by first-principles calculations. It is illustrated that both the two phases have Curie temperature 6 (4) times higher than monolayer CrI3 and VI3. The reason can be partly attributed to their large magnetic anisotropy energy (the maximum value reaches 412.9 μeV/atom). More importantly, the Curie temperature shows an electric field and strain dependent character and can even surpass room temperature under a moderate strain range. At last, we believe that the bimetal transition iodide V2Cr2I9 monolayer would support potential opportunities for spintronic devices.