First-principles study on the half-metallic properties of the VA group atoms adsorbed on WS₂ monolayer

Adsorption of atoms on the surface of two-dimensional (2D) materials is one of the most effective ways to induce magnetic properties. In this study, the atomic structure, electronic structure, magnetic properties, and strain effects of VA group atoms (N, P, As, Sb and Bi) adsorbed on a WS2 monolayer are systematically studied using a first-principles method. After calculating the adsorption energy, it was determined that all of the VA group atoms showed a preference for being directly adsorbed above the S atoms. Based on the analysis of the orbital projection density of states and charge transfer, it appears that the group VA atoms chemisorb onto the WS2 layer. The adsorption of the VA group atoms on a WS2 monolayer will introduce 1 & mu;(B) magnetic moment into the system. It is exciting that WS2 monolayer adsorbed with P, As, Sb or Bi is half-metallic with 100% spin polarization at the Fermi level. Furthermore, the magnetic properties are robust in the range of 10% strain and the magnetic moment of the system can be effectively controlled by tensile strain. In addition, when two or four atoms are adsorbed on a monolayer WS2 supercell, the adatoms show a tendency towards alignment in terms of their local magnetic moments, which may indicate a potential for ferromagnetic ordering in the system. After the adsorption of VA group atoms, monolayer WS2 exhibits structural stability, tunable magnetism under strain, 100% spin polarizability, and potential for ferromagnetism, making it a promising material for spintronic device applications.