Modulating above-room-temperature magnetism in Ga-implanted Fe5GeTe2 van der Waals magnets
Yanan Yuan, Daxiang Liu, Jingjing Yu, Guanhua Zhang, Xiang Chen, Ruiqi Liu, Siyu Wang, Fangfang Pei, Long Wei, Zhi Li, Junming Guo, Shouguo Wang, Zhaoliang Liao, Wensheng Yan, Ziqiang Qiu, Mengmeng Yang, Qian Li- General Engineering
- General Materials Science
The creation of van der Waals (vdW) ferromagnets with tunable Curie temperature (TC) and magnetic anisotropy is essential in developing vdW magnet-based devices. Here, we report an effective and reliable method for modulating the magnetic properties of vdW Fe5GeTe2 by site-specific Ga+ implantation. In this study, we report an easy axis in the ab-plane for bulk Fe5GeTe2 (TC = 310 K) and an axis out of the plane for thin Fe5GeTe2 flakes (TC = 290 K). Combining element-resolved photoemission electron microscopy and spatially resolved magneto-optic Kerr microscopy, we find that the implantation of a tiny amount of 10−3 Ga+·Å−3 in Fe5GeTe2 greatly enhances the TC from 290 to 360 K and switches the magnetic easy axis from the out-of-plane c axis to the ab-plane. The room-temperature x-ray magnetic circular dichroism signal is enhanced from 0% to 9% at an implantation level of 10−2 Ga+·Å−3. These results provide new opportunities for tailoring the magnetic properties of vdW materials beyond room temperature.