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

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 CrI3 and Cr2Ge2Te6 insulators, itinerant ferromagnetic Fe3GeTe2 (FGT), which has a larger intrinsic perpendicular anisotropy, higher Curie temperature (TC), 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 FePS3. The magneto‐optical Kerr effect results show that the TC 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.

Recent Advances in 2D Layered Phosphorous Compounds

“…successfully observed the improved ferromagnetic property of 2D FePS 3 /Fe 3 GeTe 2 heterostructure through MOKE measurement (Figure 6c). [ 111 ] Benefitting from the proximity coupling effect, the heterostructure shows higher Curie temperature and much stronger coercive field than Fe 3 GeTe 2 flakes alone. [ 111 ] Recent work has demonstrated that the antiferromagnetic phase transition in 2D FePS 3 flakes can be probed by nanomechanical resonators and revealed that specific heat plays a mediated role between mechanical motion and antiferromagnetic order (Figure 6d,e).…”

“…[ 111 ] Benefitting from the proximity coupling effect, the heterostructure shows higher Curie temperature and much stronger coercive field than Fe 3 GeTe 2 flakes alone. [ 111 ] Recent work has demonstrated that the antiferromagnetic phase transition in 2D FePS 3 flakes can be probed by nanomechanical resonators and revealed that specific heat plays a mediated role between mechanical motion and antiferromagnetic order (Figure 6d,e). [ 22 ] Moreover, the strong dependence between the Neel temperature and electrostatically induced strain in 2D FePS 3 flakes has also been confirmed.…”

“…Reproduced with permission. [ 111 ] Copyright 2020, Wiley‐VCH GmbH. d) The curves of resonance frequency varying with temperature under different voltages.…”

Spin‐Orbit Torque in Van der Waals‐Layered Materials and Heterostructures

“…Assembling the vdW heterostructure with other materials may also be helpful in enhancing the T C of vdW magnets. [163,171,172] In addition, doping, such as, Ga implantion and Co doping were recently demonstrated to be effective to increase the T C . [173][174][175] Finally, wafer-scale scalability of vdW materials is still an important issue.…”

Synthesis of 2D ternary layered manganese phosphorous trichalcogenides towards ultraviolet photodetection

“…2D MPTs exhibit larger bandgaps than current 2D transition metal chalcogenides (TMDs), which satisfies the application demands in the broad wavelength response [9]. Accordingly, 2D MPTs are supposed to provide appealing prospects in photodetection, catalysis, and spintronic devices, and expected to be a powerful candidate of next-generation electronics [10][11][12].…”