Magnetically induced ferroelectrics in multiferroics provide an optimal approach to pursuit intrinsically strong magnetoelectricity. However, the complex antiferromagnetism, faint magnetically induced polarization, and low working temperatures make their magnetoelectric performance incompetent from the applications demands. Here, a family of two-dimensional 5d halides OsX2 monolayers is predicted to be ferroelectric and ferromagnetic above room temperature. More interestingly, benefiting from the strong spin-orbital coupling and high-spin state of Os2+ ion, the magnetically induced ferroelectric polarization can reach 5.9μC/cm2, a record-large value in type-II multiferroics. The magnetoelectric effect, that is, controlling ferroelectric polarization by magnetic field has been demonstrated, and magnetically driven ferrovalley also emerges in this system. This work provides an effective way to solve the main defects of type-II multiferroics.
@article{arxiv.2409.18366,
title = {Record-large magnetically driven polarization in room temperature ferromagnets Os$X_2$ monolayers},
author = {Ying Zhou and Haoshen Ye and Junting Zhang and Shuai Dong},
journal= {arXiv preprint arXiv:2409.18366},
year = {2024}
}