Heteroepitaxy of 2D CuCr₂ Te₄ with Robust Room-temperature Ferromagnetism

Magnetic materials in 2D have attracted widespread attention for their intriguing magnetic properties. 2D magnetic heterostructures can provide unprecedented opportunities for exploring fundamental physics and novel spintronic devices. Here, the heteroepitaxial growth of ferromagnetic CuCr₂ Te₄ nanosheets is reported on Cr₂ Te₃ and mica by chemical vapor deposition. Magneto-optical Kerr effect measurements reveal the thickness-dependent ferromagnetism of CuCr₂ Te₄ nanosheets on mica, where a decrease of Curie temperature (T_C ) from 320 to 260 K and an enhancement of perpendicular magnetic anisotropy with reducing thickness are observed. Moreover, lattice-matched heteroepitaxial ultrathin CuCr₂ Te₄ on Cr₂ Te₃ exhibits an enhanced robust ferromagnetism with T_C up to 340 K due to the interfacial charge transfer. Stripe-type magnetic domains and single magnetic domain are discovered in this heterostructure with different thicknesses. The work provides a way to construct robust room-temperature 2D magnetic heterostructures for functional spintronic devices.