Robust Half-Metallicity and Perfect Spin Filtering in 2D oxide layer

We use first-principles calculations to demonstrate the transition metal oxide monolayer (ML) of Cr₂O₃ as an ideal candidate for next-generation spintronics applications. Cr₂O₃ ML has a honeycomb-kagome lattice that possesses the kagome band characteristics, where the Dirac and strongly correlated fermions coexist around the Fermi level. Furthermore, the classical Heisenberg Hamiltonian shows strong FM interactions between Cr spins, and the Cr³⁺ ions are in a low-spin state leading to a spin S = 3/2. Cr₂O₃ ML possesses a robust half-metallic behavior with a large spin gap of ~ 3.9 eV and a high T_C = 190 K. We also find that Cr₂O₃ ML displays an intrinsic Ising ferromagnetism with a giant PMAE of ~ 0.9 meV. More importantly, NEGF calculations reveal that the Cr₂O₃ ML exhibits an excellent spin filtering effect.