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

Abstract

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 μeV 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.