Uncovering A Two-Dimensional Semiconductor with Intrinsic Ferromagnetism at Room Temperature

Abstract: Two-dimensional materials have been gaining great attention as they displayed a broad series of electronic properties that ranging from superconductivity to topology. Among them, those which possess magnetism are most desirable, enabling us to manipulate charge and spin simultaneously. Here, based on first-principles calculation, we demonstrate monolayer chromium iodide arsenide (CrIAs), an undiscovered stable two-dimensional material, is an intrinsic ferromagnetic semiconductor with out-of-plane spin magnetization. The indirect bandgaps are predicted to be 0.32 eV for majority spin and 3.31 eV for minority spin, large enough to preserve semiconducting features at room temperature. Its Curie temperature, estimated by Heisenberg model with magnetic anisotropic energy using Monte Carlo method, is as high as 655 K that well above the room temperature, owing to strong direct exchange interaction between chromium d and iodine p orbitals. This work offers the affirmative answer of whether there exists two-dimensional ferromagnetic semiconductor at room temperature. And the practical realization of quantum spintronic devices, which have been suppressed because of lacking suitable room temperature magnetic materials, would embrace a great opportunity.