Coexistence of magnetism in SnX (X = S, Se, Te) monolayers by the adsorption of 3d transition-metal atoms

Abstract

Magnetism can be induced in two-dimensional (2D) group IV monochalcogenide monolayers (MLs) by the decoration of transition-metal (TM) atoms. The induced magnetism in the group IV monochalcogenides enhances their potentiality in 2D spintronic devices, which has attracted extensive attention nowadays. In this context, the structural, electronic, and magnetic properties of transition metal atoms (Mn, Fe, Co) adsorbed SnX (X = S, Se, Te) MLs are investigated by using first-principles calculations. The TM atoms adsorbed SnX MLs are found to be energetically stable with the pnma space-group, and show the semiconducting nature with electronic band gaps in the range of 0.52–1.05 eV revealing the negligible spin–orbit coupling effect in most of the studied systems. The asymmetry between spin majority and spin minority channels is revealed in the electronic density of states of the adsorbed systems, which is mainly contributed by the hybridization of the 3d orbitals of TM atoms with the 4p and 4s orbitals of Sn and X atoms. Magnetic states are realized for SnX atoms in the adsorbed systems with the induced magnetic moments between −0.03 to −0.33 μB, which indicates the antiferromagnetic alignment between TM atoms and neighboring SnX atoms. Co adsorbed SnSe and Fe adsorbed SnTe MLs are found to have significant magneto-crystalline anisotropy energy values of 0.37 and 0.84 meV/TM atom, respectively, with the preferred perpendicular direction. In addition, the p-type doping is induced in the SnX MLs as indicated by the calculation of charge transfer between the adsorbed TM and SnX atoms. The results demonstrate potential applications of TM atoms adsorbed SnX MLs for spintronic and magnetic storage devices.