Polarity‐Reversal of Exchange Bias in van der Waals FePS <sub>3</sub> /Fe <sub>3</sub> GaTe <sub>2</sub> Heterostructures
Han Xiao, Bingbing Lyu, Mengjuan Mi, Jian Yuan, Xiandong Zhang, Lixuan Yu, Qihui Cui, Chaofan Wang, Jun Song, Mingyuan Huang, Yufeng Tian, Liang Liu, Takashi Taniguchi, Kenji Watanabe, Min Liu, Yanfeng Guo, Shanpeng Wang, Yilin Wang
Abstract
Abstract Exchange bias (EB) in antiferromagnetic (AFM)/ferromagnetic heterostructures is crucial for the advancement of spintronic devices and has attracted significant attention. The common EB effect in van der Waals heterostructures features a low blocking temperature ( T b ) and a single polarity. In this work, a significant EB effect with a T b up to 150 K is observed in FePS 3 /Fe 3 GaTe 2 heterostructures, and in particular, the EB exhibits an unusual temperature‐dependent polarity‐reversal behavior. Under a high positive field‐cooling condition (e.g., μ 0 H ≥ 0.5 T), a negative EB field ( H EB ) is observed at low temperatures, and with increasing temperature, the H EB crosses zero at ≈20 K, subsequently becomes positive and later approaches zero again at T b . A model composed of a top FePS 3 /interfacial FePS 3 /Fe 3 GaTe 2 sandwich structure is proposed. The charge transfer from Fe 3 GaTe 2 to FePS 3 at the interface induces net magnetic moments (∆ M ) in FePS 3 . The interface favors AFM coupling, and thus the reversal of ∆ M of the interfacial FePS 3 leads to the polarity‐reversal of EB. Moreover, the EB can be extended to the bare Fe 3 GaTe 2 region of the Fe 3 GaTe 2 flake partially covered by FePS 3 . This work provides opportunities for a deeper understanding of the EB effect and opens a new route toward constructing novel spintronic devices.