Intrinsic ferromagnetism with high Curie temperature in two dimensional XCrY₃ (X = Al, Ga, In; Y = S, Se, Te) monolayers

Two-dimensional (2D) intrinsic ferromagnetic (FM) semiconductors with high Curie temperature are promising candidates for applications in spintronics. Here, we predict a new class of materials, XCrY3 (X = Al, Ga, In; Y = S, Se, Te) monolayers, by using density functional theory. We systematically study their stability, electronic structures and magnetism. Phonon spectra and MD simulations verify that the XCrY3 monolayers are thermodynamically stable in an ambient environment. They all have a FM ground state and some of them have large perpendicular magnetocrystalline anisotropy energies, up to 1763 mu eV per cell for monolayer InCrTe3. Monte Carlo simulations show that the Curie temperatures are between 284 and 351 K for these monolayers, which are near or even exceed room temperature. In addition, GaCrSe3 and InCrTe3 monolayers have desirable direct band gaps. The findings in this work suggest that 2D-XCrY3 may be promising candidates for applications in spintronic devices and will promote further theoretical and experimental studies.