Robust ferromagnetism in wafer-scale Fe3GaTe2 above room-temperature

The discovery of ferromagnetism in van der Waals (vdW) materials has enriched the understanding of two-dimensional (2D) magnetic orders and opened new avenues for fundamental physics research and next generation spintronics. However, achieving ferromagnetic order at room temperature, along with strong perpendicular magnetic anisotropy, remains a significant challenge. In this work, we report wafer-scale growth of vdW ferromagnet Fe₃GaTe₂ using molecular beam epitaxy. The epitaxial Fe₃GaTe₂ films exhibit robust ferromagnetism, exemplified by high Curie temperature (T_C = 420 K) and large perpendicular magnetic anisotropy (PMA) constant K_U = 6.7 × 10⁵ J/m³ at 300 K for nine-unit-cell film. Notably, the ferromagnetic order is preserved even in the one-unit-cell film with T_C reaching 345 K, benefiting from the strong PMA (K_U = 1.8×10⁵ J/m³ at 300 K). In comparison to exfoliated Fe₃GaTe₂ flakes, our epitaxial films with the same thickness show the significant enhancement of T_C, which could be ascribed to the tensile strain effect from the substrate. The successful realization of wafer-scale ferromagnetic Fe₃GaTe₂ films with T_C far above room temperature represents a substantial advancement (in some aspects or some fields, e.g. material science), paving the way for the development of 2D magnet-based spintronic devices.