  Van der Waals (vdW) heterostructures combining layered ferromagnets and other
two-dimensional (2D) crystals are promising building blocks for the realization
of ultra-compact devices with integrated magnetic, electronic and optical
functionalities. Their implementation in various technologies depends strongly
on the development of a bottom-up scalable synthesis approach allowing to
realize highly uniform heterostructures with well-defined interfaces between
different 2D layered materials. It also requires that each material component
of the heterostructure remains functional, which ideally includes ferromagnetic
order above room temperature for 2D ferromagnets. Here, we demonstrate
large-area growth of Fe$_{5-x}$GeTe$_{2}$/graphene heterostructures achieved by
vdW epitaxy of Fe$_{5-x}$GeTe$_{2}$ on epitaxial graphene. Structural
characterization confirmed the realization of a continuous vdW heterostructure
film with a sharp interface between Fe$_{5-x}$GeTe$_{2}$ and graphene. Magnetic
and transport studies revealed that the ferromagnetic order persists well above
300 K with a perpendicular magnetic anisotropy. In addition, epitaxial graphene
on SiC(0001) continues to exhibit a high electronic quality. These results
represent an important advance beyond non-scalable flake exfoliation and
stacking methods, thus marking a crucial step toward the implementation of
ferromagnetic 2D materials in practical applications.
