Two-Dimensional Os 2 Se 3 Nanosheet: A Ferroelectric Metal with Room-Temperature Ferromagnetism

作者：Cuiju Yu, Jing Cheng, Yuzhuo Zhang, Zhao Liu, Xiaofeng Liu, Chao Jia, Xingxing Li, Jinlong Yang · 发表于：The Journal of Physical Chemistry Letters · 年份：2024 · DOI：10.1021/acs.jpclett.4c00524 · 被引用次数：14 · 研究领域：2D Materials and Applications、Topological Materials and Phenomena、Machine Learning in Materials Science

Two-dimensional (2D) ferroelectric metals (FEMs) possess intriguing characteristics, such as unconventional superconductivity and the nonlinear anomalous Hall effect. However, their occurrence is exceedingly rare due to mutual repulsion between ferroelectricity and metallicity. In addition, further incorporating other features like ferromagnetism into FEMs to enhance their functionalities poses a significantly greater challenge. Here, via first-principles calculations, we demonstrate a case of an FEM that features a coexistence of room-temperature ferromagnetism, ferroelectricity, and metallicity in a thermodynamically stable 2D Os 2 Se 3 . It presents a vertical electric polarization of 3.00 pC/m that exceeds those of most FEMs and a moderate polarization switching barrier of 0.22 eV per formula unit. Moreover, 2D Os 2 Se 3 exhibits robust ferromagnetism (Curie temperature T C ≈ 527 K) and a sizable magnetic anisotropy energy (−30.87 meV per formula unit). Furthermore, highly magnetization-dependent electrical conductivity is revealed, indicative of strong magnetoelectric coupling. Berry curvature calculation suggests that the FEM might exhibit nontrivial band topology.