Proximity‐Coupling‐Induced Significant Enhancement of Coercive Field and Curie Temperature in 2D van der Waals Heterostructures

TLDR

Two‑dimensional magnetism, especially in itinerant ferromagnets like Fe₃GeTe₂, offers a platform for room‑temperature spintronic applications, and engineering 2D heterostructures can tailor their optical, electrical, and quantum properties. This study investigates whether coupling Fe₃GeTe₂ thin flakes to the antiferromagnet FePS₃ can modulate their ferromagnetic behavior. Proximity coupling to FePS₃ raises Fe₃GeTe₂’s Curie temperature by over 30 K, doubles its coercive field, and alters its interfacial spin textures, demonstrating that antiferromagnet/ferromagnet interfaces can engineer itinerant 2D ferromagnets for advanced magnetic devices.

Abstract

Abstract Magnetism in 2D has long been the focus of condensed matter physics due to its important applications in spintronic devices. A particularly promising aspect of 2D magnetism is the ability to fabricate 2D heterostructures with engineered optical, electrical, and quantum properties. Recently, the discovery of intrinsic ferromagnetisms in atomic thick materials has provided a new platform for investigations of fundamental magnetic physics. In contrast to 2D CrI 3 and Cr 2 Ge 2 Te 6 insulators, itinerant ferromagnetic Fe 3 GeTe 2 (FGT), which has a larger intrinsic perpendicular anisotropy, higher Curie temperature ( T C ), and relatively better stability, is a promising candidate for achieving permanent room‐temperature ferromagnetism through interface or component engineering. Here, it is shown that the ferromagnetic properties of FGT thin flakes can be modulated through coupling with a FePS 3 . The magneto‐optical Kerr effect results show that the T C of FGT is improved by more than 30 K and that the coercive field is increased by ≈100% due to the proximity coupling effect, which changes the spin textures of FGT at the interface. This work reveals that antiferromagnet/ferromagnet coupling is a promising way to engineer the magnetic properties of itinerant 2D ferromagnets, which paves the way for applications in advanced magnetic spintronic and memory devices.