Liu Daxiang, Pei Fangfang, Wang Siyu, Chen Xiaoli, Yuan Yanan, Zhao Jiapeng, Guo Junming, Wang Tianye, Li Lin, Kan Xucai, Liao Zhaoliang, Song Dongsheng, Liu Xue, Fang Yong, Wang Shouguo, Zhou Shiming, Qiu Zi Qiang, Huang He, Yang Mengmeng, Li Qian
National Synchrotron Radiation Laboratory, and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230029, China.
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
ACS Nano. 2024 Aug 27;18(34):23812-23822. doi: 10.1021/acsnano.4c09142. Epub 2024 Aug 15.
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 FeGaTe 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 FeGaTe as an emerging room-temperature-operating vdW material and paving the way for designing practical 2D spintronic devices.
作为交换偏置（EB）的宿主，范德华（vdW）磁性材料展现出了与传统磁性材料不同的有趣且独特的功能。大多数vdW系统中的EB远低于室温，这对实际应用构成了挑战。在此，通过克尔显微镜，我们展示了在天然氧化的二维（2D）vdW铁磁FeGaTe纳米片中，接近室温的创纪录高阻塞温度以及在100 K时接近2 kOe的巨大正EB场。此外，我们通过训练磁场实现了对EB的有无和正负号的可逆操纵，而无需多次场冷却过程。因此，我们的研究清楚地揭示了vdW磁性材料中高达近室温的强大、可观且符号可调的EB，从而确立了FeGaTe作为一种新兴的室温工作vdW材料，并为设计实用的2D自旋电子器件铺平了道路。
