Room-temperature intrinsic ferromagnetism in epitaxial CrTe2 ultrathin films

While the discovery of two-dimensional (2D) magnets opens the door for fundamental physics and next-generation spintronics, it is technically challenging to achieve the room-temperature ferromagnetic (FM) order in a way compatible with potential device applications. Here, we report the growth and properties of single- and few-layer CrTe₂, a van der Waals (vdW) material, on bilayer graphene by molecular beam epitaxy (MBE). Intrinsic ferromagnetism with a Curie temperature (T_C) up to 300 K, an atomic magnetic moment of ~0.21 μ_B?/Cr and perpendicular magnetic anisotropy (PMA) constant (K_u) of 4.89 × 10⁵ erg/cm³ at room temperature in these few-monolayer films have been unambiguously evidenced by superconducting quantum interference device and X-ray magnetic circular dichroism. This intrinsic ferromagnetism has also been identified by the splitting of majority and minority band dispersions with ~0.2 eV at D point using angle-resolved photoemission spectroscopy. The FM order is preserved with the film thickness down to a monolayer (T_C ~ 200 K), benefiting from the strong PMA and weak interlayer coupling. The successful MBE growth of 2D FM CrTe₂ films with room-temperature ferromagnetism opens a new avenue for developing large-scale 2D magnet-based spintronics devices.