Wang Jicheng, Ding Shilei, Ding Bei, Hou Zhipeng, Peng Licong, Jiang Yilan, Zheng Fengshan, Luo Zhaochu, Ye Yu, Yang Jinbo, Hou Yanglong, Wu Rui
Spin-X Institute, School of Physics and Optoelectronics, State Key Laboratory of Luminescent Materials and Devices, and Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, South China University of Technology, Guangzhou 511442, P.R. China.
Department of Materials, ETH Zürich, Zürich 8093, Switzerland.
ACS Nano. 2025 Sep 11. doi: 10.1021/acsnano.5c08572.
Exchange bias (EB) effects play a crucial role in modern magnetic memory technology. Recently, the van der Waals heterostructures have shown potential for investigating mechanisms of the EB effect owing to their tunable physical properties and flexibility in fabrication. However, due to low magnetic ordering temperatures for most van der Waals magnets, establishing EB in van der Waals antiferromagnet/ferromagnet heterostructures at room temperature is challenging. In this study, we fabricate (FeCo)GeTe (FCGT)/FeGaTe (FGaT) heterostructures with magnetic ordering temperatures of each component well above room temperature to achieve a room-temperature EB effect. It is found that the sign and magnitude of the EB field can be efficiently controlled by manipulating the Néel order of FCGT. The manipulation of the Néel order shows significant magnetic field dependence. A strong preset field induces a switch in the Néel order of FCGT, which aligns the interfacial magnetization at the FCGT/FGaT interface, leading to robust EB, as revealed by both transport measurements and macrospin model calculations. Our findings demonstrate the intrinsic manipulation and switchability of room-temperature EB in all-van der Waals heterostructures and further emphasize the potential of two-dimensional spintronic devices.
交换偏置（EB）效应在现代磁存储技术中起着至关重要的作用。最近，范德华异质结构因其可调的物理性质和制造灵活性，在研究EB效应的机制方面显示出潜力。然而，由于大多数范德华磁体的磁有序温度较低，在室温下在范德华反铁磁体/铁磁体异质结构中建立EB具有挑战性。在本研究中，我们制备了（FeCo）GeTe（FCGT）/FeGaTe（FGaT）异质结构，其各组分的磁有序温度远高于室温，以实现室温EB效应。研究发现，通过操纵FCGT的奈尔序，可以有效地控制EB场的符号和大小。奈尔序的操纵表现出显著的磁场依赖性。如输运测量和宏观自旋模型计算所示，强预设场会诱导FCGT的奈尔序发生转变，从而使FCGT/FGaT界面处的界面磁化方向一致，进而产生稳健的EB。我们的研究结果证明了全范德华异质结构中室温EB的本征操纵和可切换性，并进一步强调了二维自旋电子器件的潜力。
