The curvature-induced magnetization in CrI3 bilayer: flexomagnetic effect enhancement in van der Waals antiferromagnets

TL;DR

This paper demonstrates that CrI3 bilayer exhibits a significantly enhanced flexomagnetic effect due to its antiferromagnetic structure, with potential applications in spintronics and straintronics.

Contribution

First principle calculations reveal a large flexomagnetic effect in CrI3 bilayer, highlighting the role of its antiferromagnetic structure and interlayer distance.

Findings

Flexomagnetic effect in CrI3 bilayer is estimated at 200 μB/Å.

The effect is two orders of magnitude higher than in Mn3GaN.

Strain-dependent ferromagnetic coupling and large interlayer distance enhance the effect.

Abstract

The bilayer of CrI3 is a prototypical van der Waals 2D antiferromagnetic material with magnetoelectric effect. It is not generally known, however, that for symmetry reasons the flexomagnetic effect, i.e., the strain gradient-induced magnetization, is also possible in this material. In the present paper, based on the first principle calculations, we estimate the flexomagnetic effect to be 200 {\mu}B{\AA} that is two orders of magnitude higher than it was predicted for the referent antiperovskite flexomagnetic material Mn3GaN. The two major factors of flexomagnetic effect enhancement related to the peculiarities of antiferromagnetic structure of van der Waals magnets is revealed: the strain-dependent ferromagnetic coupling in each layer and large interlayer distance separating antiferromagnetically coupled ions. Since 2D systems are naturally prone to mechanical deformation, the emerging field of flexomagnetism is of special interest for application in spintronics of van der Waals materials and straintronics in particular.