Anomalous Magnetization in a van der Waals Antiferromagnet/Ferromagnet CrCl3/Fe3GeTe2/CrCl3 Heterostructure

Manipulating and designing the interfaces between two-dimensional (2D) van der Waals materials serves as a fundamental approach for achieving technologically significant effects and tailoring material characteristics. The exchange bias effect exhibited in 2D van der Waals magnetic heterostructures has garnered significant attention in the realm of spintronics research owing to its intriguing physics and promising prospects for practical applications. Herein, we have, for the first time, constructed the CrCl₃/Fe₃GeTe₂/CrCl₃ heterostructure and employed the anomalous Hall method to precisely measure its unique characteristics. Interestingly, distinct double-shifted hysteresis loops observed in the anomalous Hall effect curve are attributed to the emergence of multiple domains within the Fe₃GeTe₂ layer induced by the CrCl₃/Fe₃GeTe₂ interfaces. In contrast to the pure Fe₃GeTe₂ few-layer structures, the CrCl₃/Fe₃GeTe₂/CrCl₃ heterostructure demonstrates the presence of an exchange bias effect. As the temperature increases, the values of the exchange bias field decrease and ultimately vanish at 11 K, near the Néel temperature of CrCl₃. Concurrently, the width of the hysteresis loop diminishes and disappears above 150 K. These findings suggest that the pinning effect and exchange bias effect are not present simultaneously, and the pinning effect has a temperature range wider than that of the exchange bias effect. Our findings underscore the potential of antiferromagnet–ferromagnet coupling interfaces as a powerful means for manipulating magnetic properties, with implications for both advanced spintronic device design and fundamental understanding of magnetic interactions.