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 heterointerfaceinduced 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.

Controlling bimerons as skyrmion analogues by ferroelectric polarization in 2D van der Waals multiferroic heterostructures

“…In the easy-axis 2D magnets, skyrmions are usually of the Néeltype, whereas in the easy plane 2D magnet, skyrmions usually exist in bimerons form [33][34][35] . When 2D FE and FM materials are combined to form atomic layer-thick multiferrous vdW HSs, such 2D system endows nonvolatile coupling between two ferroic orderings [36][37][38] , compensating the scarcity of the single-phase multiferroic material. Furthermore, nonvolatile FE polarization controlled magnetic skyrmions through the magnetoelectric coupling effect is highly anticipated in such systems.…”

Two-Dimensional Ferroelastic Semiconductors in Nb2SiTe4 and Nb2GeTe4 with Promising Electronic Properties

“…The recent interest in 2D ferroelastic crystals not only lies in ferroelasticity itself but also extends to the coupling of ferroelasticity and electronic properties. [11][12][13][14] Compared with 2D crystals presenting ferroelastic order only, undoubtedly, 2D crystals that hold ferroelasticity and intriguing electronic properties simultaneously are more desirable as they will open up unprecedented opportunities for developing multifunctional and controllable devices. Currently, there are mainly two types of such coupling in 2D crystals.…”

Two dimensional ferroelectrics: Candidate for controllable physical and chemical applications

“…Besides metallic graphene, the electronic structures of semiconducting WSe 2 can be also modulated by FE In 2 Se 3 layer; the induced band shift leads to a significant band gap reduction and staggered band alignment when electric dipole orientation is reversed. For example, in the CrI 3 /Sc 2 CO 2 heterostructures, 82 2H‐MoS 2 /In 2 Se 3 78 and InTe/In 2 Se 3 heterostructure, 79 the band alignment is closely dependent on the polarization of 2D ferroelectrics, due to the different responses to the two contacted polar surfaces, see Figure 4c. As a result, the electron transfer and associated electronic properties of the heterostructures will be modulated by the ferroelectric switch.…”