Intrinsic ferromagnetism and the quantum anomalous Hall effect in two-dimensional MnOCl2 monolayers

Guang Song; Chengfeng Zhang; Tengfei Xie; Qingkang Wu; Bingwen Zhang; Xiaokun Huang; Zhongwen Li; Guannan Li; Benling Gao

doi:10.1039/d2cp02384a

Intrinsic ferromagnetism and the quantum anomalous Hall effect in two-dimensional MnOCl₂ monolayers

Phys Chem Chem Phys. 2022 Aug 31;24(34):20530-20537. doi: 10.1039/d2cp02384a.

Authors

Guang Song¹, Chengfeng Zhang¹, Tengfei Xie¹, Qingkang Wu¹, Bingwen Zhang², Xiaokun Huang³, Zhongwen Li¹, Guannan Li¹, Benling Gao¹

Affiliations

¹ Department of Physics, Huaiyin Institute of Technology, Huaian 223003, China. gsong@hyit.edu.cn.
² Fujian Key Laboratory of Functional Marine Sensing Materials, Minjiang University, Fuzhou 350108, China.
³ School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333001, China.

PMID: 35996999
DOI: 10.1039/d2cp02384a

Abstract

Due to their potential application in spintronic devices, two-dimensional (2D) ferromagnetic materials are highly desired. We used first-principles calculations and Monte Carlo simulations to investigate the electronic structure and magnetic characteristics of the MnOCl₂ monolayers. We discovered two stable monolayer structures, Pmna-MnOCl₂ and Pmmn-MnOCl₂. Our findings show that the Pmna-MnOCl₂ monolayer is an intrinsic ferromagnetic semiconductor with an indirect band gap of 0.152 eV and a Curie temperature (T_C) of 202 K, while the Pmmn-MnOCl₂ monolayer is an intrinsic ferromagnetic Dirac semimetal with a high T_C (910 K) and triaxial magnetic anisotropy. We also show that a Pmmn-MnOCl₂ monolayer with a nontrivial band gap of 6.2 meV can achieve the quantum anomalous Hall effect (QAHE) with Chern number C = 1. Additionally, the existence of a gapless edge state can be flexibly regulated by choosing the terminal edges. Our studies reveal that the Pmmn-MnOCl₂ monolayer can serve as a candidate material to achieve high-temperature QAHE.