Magnetic Anisotropy and Jahn–Teller Effect in Ferromagnetic Two-Dimensional CrGa₂Te₄

The transition metal (TM)-based two-dimensional (2D) materials show great promise for realizing ultrathin spintronic devices because of their structural and magnetic properties. In this work, we predict the ferromagnetic ground state of the CrGa2Te4 monolayer with an α-FeGa2S4-1T type phase. The first-principles calculations and Monte Carlo simulations indicate that this monolayer is a ferromagnetic half-metal possessing a Curie temperature of 277 K. It is revealed in this system that the further splitting of Cr-eg orbitals results in a high-spin configuration of Cr2+ with an out-of-plane easy axis. A physical picture of the magneto-crystalline anisotropy affected by the Jahn–Teller distortion in the GrCa2Te4 monolayer is obtained. This work expands our understanding of the magnetic phenomena to 2D octahedral coordinated crystals.