Microscopic magnetic properties of two-dimensional magnetic FexGeTe2 films on graphene

Scalable fabrication of magnetic 2D materials and heterostructures constitutes a crucial step for scaling down current spintronic devices and the development of novel spintronic applications. With this prospect, we have recently succeeded in growing high quality and large area Fe3GeTe2 (F3GT) and Fe5-xGeTe2 (F5GT) epitaxial films via molecular beam epitaxy (MBE) on graphene/SiC(0001) templates. This 2D magnet is extremely promising for such applications, given its highly tunable properties and large potential for room temperature ferromagnetism (FM). Morphological and structural characterization of the films confirmed the realization of large-area, continuous layers with stable interfaces with graphene, and good crystalline quality. Magneto-transport and x-ray magnetic circular dichroism investigations confirmed a robust out-of-plane FM in the layers of F3GT with a Curie temperature of around 220 K. More interestingly, our most recent XMCD findings suggest that F5GT layers exhibit FM up to around 320 K. These results are comparable to state-of-the-art exfoliated flakes from bulk crystals and are highly relevant for further research on wafer-scale growth of van der Waals heterostructures combining FGT with other layered crystals such as transition metal dichalcogenides for the realization of multifunctional, atomically thin devices.