Tunable Room-Temperature Ferromagnetism in Two-Dimensional Cr2Te3

Yao Wen; Zhehong Liu; Yu Zhang; Congxin Xia; Baoxing Zhai; Xinhui Zhang; Guihao Zhai; Chao Shen; Peng He; Ruiqing Cheng; Lei Yin; Yuyu Yao; Marshet Getaye Sendeku; Zhenxing Wang; Xubing Ye; Chuansheng Liu; Chao Jiang; Chongxin Shan; Youwen Long; Jun He

doi:10.1021/acs.nanolett.9b05128

Tunable Room-Temperature Ferromagnetism in Two-Dimensional Cr₂Te₃

Nano Lett. 2020 May 13;20(5):3130-3139. doi: 10.1021/acs.nanolett.9b05128. Epub 2020 Apr 30.

Authors

Yao Wen¹, Zhehong Liu², Yu Zhang¹, Congxin Xia³, Baoxing Zhai³, Xinhui Zhang⁴, Guihao Zhai⁴, Chao Shen⁴, Peng He⁵, Ruiqing Cheng⁵, Lei Yin⁵, Yuyu Yao⁵, Marshet Getaye Sendeku⁵, Zhenxing Wang⁵, Xubing Ye², Chuansheng Liu¹, Chao Jiang⁵, Chongxin Shan⁶, Youwen Long^{2

7}, Jun He¹

Affiliations

¹ School of Physics and Technology, Wuhan University, Wuhan 430072, China.
² Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Department of Physics, Henan Normal University, Xinxiang 453007, China.
⁴ State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
⁶ Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, School of Physics and Engineering, Zhengzhou University, Zhengzhou 450052, China.
⁷ Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China.

PMID: 32338924
DOI: 10.1021/acs.nanolett.9b05128

Abstract

The manipulation of magnetism provides a unique opportunity for the development of data storage and spintronic applications. Until now, electrical control, pressure tuning, stacking structure dependence, and nanoscale engineering have been realized. However, as the dimensions are decreased, the decrease of the ferromagnetism phase transition temperature (T_c) is a universal trend in ferromagnets. Here, we make a breakthrough to realize the synthesis of 1 and 2 unit cell (UC) Cr₂Te₃ and discover a room-temperature ferromagnetism in two-dimensional Cr₂Te₃. The newly observed T_c increases strongly from 160 K in the thick flake (40.3 nm) to 280 K in 6 UC Cr₂Te₃ (7.1 nm). The magnetization and anomalous Hall effect measurements provided unambiguous evidence for the existence of spontaneous magnetization at room temperature. The theoretical model revealed that the reconstruction of Cr₂Te₃ could result in anomalous thickness-dependent T_c. This dimension tuning method opens up a new avenue for manipulation of ferromagnetism.

Keywords: 1 unit cell; Room-temperature ferromagnetism; anomalous Hall effect; reconstruction.