Nonvolatile electric control of magnetic anisotropy and Curie temperature in the van der Waals multiferroic heterostructure CrSBr/Al2S3.

The realization of nonvolatile electrical spin manipulation in two-dimensional (2D) van der Waals (vdW) ferromagnetic semiconductors (FMS) can overcome the problems of volatility and power consumption brought by traditional control methods in spin devices. Based on density functional theory, we study the electronic property changes and magnetoelectric coupling effects in a CrSBr/Al2S3 multiferroic heterostructure constructed with a FMS CrSBr monolayer and ferroelectric (FE) Al2S3 monolayer. The results show that switching the polarization direction of Al2S3 can achieve nonvolatile control of magnetism. The CrSBr/Al2S3 heterostructure exhibits FMS characteristics in both upward and downward polarization models and has a significant out-of-plane magnetic anisotropy. By reducing the interlayer spacing to influence the interfacial coupling effect, a remarkable change in magnetic anisotropy energy (MAE) from 310.6 µeV (out-of-plane) to -315.6 µeV (in-plane) occurs as the interlayer spacing decreases in the polarization-upward model along the [100] direction. However, in the polarization-downward model, the MAE decreases from 294.3 µeV to 54.7 µeV, still maintaining the out-of-plane pattern. The MAE on the [100] and [010] surfaces also show anisotropy. In addition, due to the introduction of the super-exchange pathway from Cr-SAl2S3-Cr to the original Cr-SCrSBr/Br-Cr in the CrSBr/Al2S3 heterostructure, the Curie temperature (TC) has been significantly increased compared to the monolayer. These findings reveal the potential application prospects of the vdW multiferroic heterostructure CrSBr/Al2S3 in nonvolatile electromagnetic control and high-density storage devices.