Manipulation of Exchange Bias in Two-Dimensional van der Waals Ferromagnet Near Room Temperature
Daxiang Liu, Fangfang Pei, Siyu Wang, Xiaoli Chen, Yanan Yuan, Jiapeng Zhao, Junming Guo, Tianye Wang, Lin Li, Xucai Kan, Zhaoliang Liao, Dongsheng Song, Xue Liu, Yong Fang, Shouguo Wang, Shiming Zhou, Zi Qiang Qiu, He Huang, Mengmeng Yang, Qian Li
Abstract
As a host for exchange bias (EB), van der Waals (vdW) magnetic materials have exhibited intriguing and distinct functionalities from conventional magnetic materials. The EB in most vdW systems is far below room temperature, which poses a challenge for practical applications. Here, by using Kerr microscopy, we demonstrate a record-high blocking temperature that approaches room temperature and a huge positive EB field that nears 2 kOe at 100 K in naturally oxidized two-dimensional (2D) vdW ferromagnetic Fe 3 GaTe 2 nanoflakes. Moreover, we realized a reversible manipulation of both the presence/absence and positive/negative signs of EB via a training magnetic field without multiple field cooling processes. Thus, our study clearly reveals the robust, sizable, and sign-tunable EB in vdW magnetic materials up to near room temperature, thereby establishing Fe 3 GaTe 2 as an emerging room-temperature-operating vdW material and paving the way for designing practical 2D spintronic devices.