Interface‐Induced Anomalous Behavior of Magnetism in FexGeTe2/Pt Bilayer

作者：Qiqi Zhang, Hongjun Xu, Zhongchen Xu, Congli He, Xinlu Li, Guibin Lan, Jia Zhang, Youguo Shi, Qinghua Zhang, Chao‐Yao Yang, Jing Chen, Yawei Gao, Chaoqun Hu, Jiahui Li, Yunchi Zhao, Huo Yuping, Jian Ge, Yu Zhang, Hao‐Kai Chang, Chi‐Yen Huang, Shipeng Shen, Yuelin Zhang, Hongxiang Wei, Guoqiang Yu, Shouguo Wang · 发表于：Advanced Functional Materials · 年份：2024 · DOI：10.1002/adfm.202414742 · 被引用次数：5 · 研究领域：2D Materials and Applications、Chalcogenide Semiconductor Thin Films、Phase-change materials and chalcogenides

Abstract Interface engineering is a promising strategy for controlling the Curie temperature ( T c ) and perpendicular magnetic anisotropy (PMA) in magnetic 2D van der Waals (2D vdWs)‐based heterostructures. However, establishing high‐quality interface structures in magnetic 2D vdWs/metal stacks, crucial for maximizing interface effects, remains a significant challenge. Here, a Fe 5‐x GeTe 2 /Pt (F5GT/Pt) prototype with a superior interface quality is achieved using a low‐power physical vapor deposition technique. The magnetic properties of the F5GT/Pt heterostructures are strongly influenced by employing the specific physical deposition method. Stable ferromagnetism at 400 K is observed when depositing Pt atoms with relatively high energy, despite the T c of pristine F5GT being below 300 K. This unexpected high‐temperature ferromagnetism is attributed to the formation of a ferromagnetic alloy at the interface, commonly present in vdWs‐based stacks fabricated through physical deposition but often overlooked. The deposit of Pt atoms with ultralow energy leads to the formation of a unique Fe 5‐x GeTe 2 /Fe 3‐x GeTe 2 heterojunction at the interface, significantly enhancing the PMA. This work emphasizes the importance of interface structures in vdWs‐based devices, suggesting that controlling the growth process offers an effective approach to construct and engineer vdWs heterostructures, thus improving the performance and introducing new functionalities to spintronic devices.