Multiferroic materials, which simultaneously exhibit ferroelectricity and magnetism, have attracted substantial attention due to their fascinating physical properties and potential technological applications. With the trends towards device miniaturization, there is an increasing demand for the persistence of multiferroicity in single-layer materials at elevated temperatures. Here, we report high-temperature multiferroicity in single-layer CuCrSe2, which hosts room-temperature ferroelectricity and 120 K ferromagnetism. Notably, the ferromagnetic coupling in single-layer CuCrSe2 is enhanced by the ferroelectricity-induced orbital shift of Cr atoms, which is distinct from both types I and II multiferroicity. These findings are supported by a combination of second-harmonic generation, piezo-response force microscopy, scanning transmission electron microscopy, magnetic, and Hall measurements. Our research provides not only an exemplary platform for delving into intrinsic magnetoelectric interactions at the single-layer limit but also sheds light on potential development of electronic and spintronic devices utilizing two-dimensional multiferroics.
@article{arxiv.2405.11485,
title = {Evidence for Multiferroicity in Single-Layer CuCrSe$_2$},
author = {Zhenyu Sun and Yueqi Su and Aomiao Zhi and Zhicheng Gao and Xu Han and Kang Wu and Lihong Bao and Yuan Huang and Youguo Shi and Xuedong Bai and Peng Cheng and Lan Chen and Kehui Wu and Xuezeng Tian and Changzheng Wu and Baojie Feng},
journal= {arXiv preprint arXiv:2405.11485},
year = {2024}
}