Electronic Structures and Magnetic Properties of Co-Adsorbed Monolayer WS2

Using the first-principles density functional theory (DFT) calculations, we study the effects of Co adatom on the electronic and magnetic properties of monolayer WS2. The calculations show that, for the high symmetry adsorption sites (Tw, H and Ts) on the surface of monolayer WS2, Co atom prefers Tw site. The p-d hybridization mechanism for the magnetism results in the splitting of the energy levels near the Fermi energy. A total magnetic moment of ~1.0 μB is found in WS2 system with one Co adsorbed and local magnetic moment which mainly focuses on the adsorption site. For Tw adsorption position, we further investigate the formation energy of the ferromagnetic (FM) and the antiferromagnetic (AFM) states under different monolayer coverage (ML) of Co atoms. The FM configurations are relatively stable at 0.50 ML and 1.0 ML. The local density of states (LDOS) and band calculations reveal that both of them present half-metal ferromagnetic materials’ property, which are the important preparation materials for spintronic devices.