Tunable magnetism in bilayer CrI₃ through heterointerface

Long-range intrinsic ferromagnetism in 2D semiconductor van der Waals materials is always a great study of interest to the research community due to their fascinating magneto-electronic and magneto-optical properties. CrI₃ monolayer in which long-range intrinsic ferromagnetic ordering has been reported in the recent past [Huang et al. Nature 546, 270 (2017)], its bilayer antiferromagnetic to ferromagnetic transition has been the subject of many attempts. Despite considerable work in this direction, there is a lack of achieving nonvolatile ferromagnetism in this material. In this work, using first-principles calculations, a detailed study is carried out to obtain nonvolatile ferromagnetism in bilayer CrI₃ due to interfacing with the WSeTe monolayer. Two different heterostructures (CrI₃/TeWSe and CrI₃/SeWTe) with different possible stacking patterns are considered for this purpose. A transition from an antiferromagnetic (AFM) to a ferromagnetic (FM) state is noticed due to interfacing with the WSeTe monolayer. In the case of CrI₃/TeWSe, a half-metallic ferromagnetic, while in the case of CrI₃/SeWTe, semiconducting ferromagnetic behaviour is computed. The responsible mechanism of super-super-exchange for this type of transition (AFM to FM) is also discussed. Our findings offer a promising avenue to obtain nonvolatile ferromagnetism in bilayer CrI₃ and also make this material a desirable platform for the creation of two-dimensional spintronics.