Room-temperature ferromagnetism and half-metallicity in monolayer orthorhombic CrS2

Two-dimensional materials with high-temperature ferromagnetism and half-metallicity have the latest applications in spintronic devices. Based on first-principles calculations, we have investigated a novel two-dimensional CrS₂ phase with an orthorhombic lattice. Our results suggest that it is stable in dynamics, thermodynamics, and mechanics. The ground state of monolayer orthorhombic CrS₂ is both ferromagnetic and half-metallic, with a high Curie temperature of 895 K and a large spin-flipping gap on values of 0.804 eV. This room-temperature ferromagnetism and half-metallicity can maintain stability against a strong biaxial strain ranging from −5% to 5%. Meanwhile, increasing strain can significantly maintain the out-of-plane magnetic anisotropy. A density of states analysis, together with the orbital-resolved magnetic anisotropy energy, has revealed that the strain-enhanced MAE is highly related to the 3d-orbital splitting of Cr atoms. Our results suggest the monolayer orthorhombic CrS₂ is an ideal candidate for future spintronics.