Intrinsic ferromagnetic half-metal: Non-equivalent alloying compounds CrMnI6 monolayer

Abstract

Spintronics, the golden era of modern magnetism.Nowadays, intrinsic two-dimensional (2D) half-metal materials with pure spin sources possess a broad prospect in the practical application of modern spintronics. Therefore, based on first-principles calculations, we systematically predict the electronic structures and magnetic properties of non-equivalent alloying compounds CrMnI6 monolayer and fortunately find that the monolayer is a dynamically and thermally stable half-metal with a large in-plane magnetic anisotropy energy (MAE) of 36.75 meV/cell. Its Curie temperature is 145 K, significantly higher than that of CrI3 monolayer. In addition, the half-metallicity of monolayer CrMnI6 can be remained in almost the entire range of carrier doping and strain. Moreover, the in-plane MAE can be further improved to 68.41 and 60.58 meV/cell under 0.1 hole doping and 6% tensile strain, respectively. Simultaneously, according to the second-order perturbation theory, the larger in-plane MAE of CrMnI6 monolayer mainly originates from the couplings of 〈pxLxpz〉 in the different spin channel of I atom and the couplings of 〈dx2-y2Lzdxy〉 in the same spin channel of Mn and Cr atoms. Our prediction of such a novel 2D FM half-metal CrMnI6 monolayer may serve as a good candidate for the next-generation high-performance spintronic nanodevices and high- density magnetic recording and sensors.