Distorted monolayer ReS2 with low-magnetic-field controlled magnetoelectricity
Distorted monolayer ReS2 with low-magnetic-field controlled magnetoelectricity
复制标题
具有低磁场控制磁电的扭曲单层ReS2
DOI：
10.1021/acsnano.8b09058
复制
发表时间：
2019
期刊：
影响因子：
17.1
通讯作者：
Wu Xinglong
中科院分区：
文献类型：
--
作者：
Zhang Jinlei;Wu Shuyi;Shan Yun;Guo Junhong;Yan Shuo;Xiao Shuyu;Yang Chunbing;Shen Jiancang;Chen Jian;Liu Lizhe;Wu Xinglong
具有铁电/铁磁序的二维材料，特别是低磁场控制的磁电在自旋电子学和多态数据存储方面具有很大的应用前景。然而，由于结构反演对称性、热致动和去极化场等因素，在原子厚二维材料中难以实现铁电偶极子和磁电偶极子。为了克服这些困难，单层结构必须具有面内反转不对称性，以提供面外铁电极化。本文采用晶体化学的方法，在单层ReS2中设计特定的原子位移来改变晶体对称性，从而在室温下诱导面外铁电极化。原子位移的ReS2单分子层中的阳离子Re空位导致两个相邻硫原子的自旋极化产生磁有序，Re空位附近的铁电畸变局部调整了铁磁有序，从而在28k左右触发了低磁场控制的ME极化。实现了二维ME耦合多铁性。我们的研究结果不仅揭示了一种在二维材料中实现铁电和铁磁有序共存的设计方法，而且还提供了对二维材料中磁电的见解。
Two dimensional (2D) materials possessing ferroelectric/ferromagnetic orders and especially low-magnetic-field controlled magnetoelectricity have great promise in spintronics and multistate data storage. However, ferroelectric and magnetoelectric (ME) dipoles in the atom-thick 2D materials are difficult to be realized due to structural inversion symmetry, thermal actuation, and depolarized field. To overcome these difficulties, the monolayer structure must possess an in-plane inversion asymmetry in order to provide out-of-plane ferroelectric polarization. Herein, crystal chemistry is adopted to engineer specific atomic displacement in monolayer ReS2 to change the crystal symmetry to induce out-of-plane ferroelectric polarization at room temperature. The cationic Re vacancy in the atom-displaced ReS2 monolayer causes spin polarization of two immediate neighbor sulfur atoms to generate magnetic ordering, and the ferroelectric distortion near the Re vacancy locally tunes the ferromagnetic order thereby triggering low-magneticfield controlled ME polarization at about 28 K. As a result, 2D ME coupling multiferroics is achieved. Our results not only reveal a design methodology to attain coexistence of ferroelectric and ferromagnetic orders in 2D materials but also provide insights into magnetoelectricity in 2D materials.