Nonvolatile Electrical Control and Heterointerface‐Induced Half‐Metallicity of 2D Ferromagnets

Abstract Electrical control of atom‐thick van der Waals (vdW) ferromagnets is a key toward future magnetoelectric nanodevices; however, state‐of‐the‐art control approaches are volatile. In this work, introducing ferroelectric switching as an aided layer is demonstrated to be an effective approach toward achieving nonvolatile electrical control of 2D ferromagnets. For example, when a ferromagnetic monolayer CrI 3 and ferroelectric MXene Sc 2 CO 2 come together into multiferroic heterostructures, CrI 3 is controlled by polarized states P↑ and P↓ of Sc 2 CO 2 . P↑ Sc 2 CO 2 does not change the semiconducting nature of CrI 3 , but surprisingly P↓ Sc 2 CO 2 makes CrI 3 half‐metallic. Nonvolatility of the electrical switching between two oppositely ferroelectric polarized states, therefore, indirectly enables nonvolatile electrical control of CrI 3 between ferromagnetic semiconductor and half‐metal. The heterointerface‐induced half‐metallicity in CrI 3 is intrinsic without resorting to any chemical functionalization or external physical modification, which is rather beneficial to the practical application. This work paves the way for nonvolatile electrical control of 2D vdW ferromagnets and applications of CrI 3 in half‐metal‐based nanospintronics.