Prediction of high spin polarization and perpendicular magnetic anisotropy in two dimensional ferromagnetic Mn2CXX’ (X, X′=F, Cl, Br, I) Janus monolayers

Abstract

Abstract Two dimensional layered transition metal carbides and nitrides, owing to their unique electronic properties, have potential applications in novel low-dimensional spintronic devices. However, only a few materials with half metallic and easy axis in perpendicular direction make possible for practical applications in spintronics. Here, the electronic structure and magnetic anisotropy of Mn 2CXX’ (X, X \xa0=\xa0F, Cl, Br, I) Janus monolayers are investigated by first-principles calculations. It is found that the Mn2CXX ′ Janus monolayers are half metallic, showing a high spin polarization at Fermi level. The magnetic anisotropy of Mn 2CXX ′ monolayers can be modulated by replacing the adsorbed atoms . Mn 2CFCl, Mn2CClI and Mn2CClBr show easy axis in perpendicular direction, while the easy axis of Mn2CFBr is in-plane direction. When biaxial strains are −2%, ±4\xa0% and −6%, the easy axis direction of Mn2CClI changes from out-of-plane to in-plane, where the total magnetic anisotropy of I atom can be regulated. The easy axis in in-plane direction comes from the hybridization between I-pz and I-px orbital. However, the easy axis of Mn2CClI maintains perpendicular direction at biaxial strains of 2\xa0% and 6\xa0%. The Mn2CXX ′ monolayers with half metallicity and easy axis in perpendicular direction have the potential applications in spintronic devices.