Magnetism in molybdenum disulphide monolayer with sulfur substituted by 3d transition metals

With sulfur partially substituted by 3d transition metals, magnetism in a molybdenum disulphide monolayer is investigated comprehensively by the calculation of a spin-polarized density functional theory. The magnetic moment induced by a single defect is found to be equal to the absolute value of the magnetic moment of this defect atom subtracted by two Bohr magnetons. A detailed analysis on the locally projected density of states demonstrates that the underlying mechanism can be qualitatively interpreted in a simple ionic scenario. Subsequently, quasi one-dimensional superlattices of defects are built for the exploration of long range magnetic orders. Among four candidates of chromium and copper superlattices for high temperature dilute magnetic semiconductors (DMSs), a particular chromium superlattice holds the promise of a room temperature DMS against the change of the on-site Coulomb interaction.