▎ 摘　　要

In this paper, we investigate stable geometries, electronic and magnetic properties of vanadium (V) atom adsorption on graphene sheet using first principles method based on density-functional theory with the generalized gradient approximation. Calculation shows that single V atom situated on the hexagonal site of graphene is the most stable configuration, where the covalent interaction is more pronounced. The projected density of states (PDOS) is also computed around the Fermi level. It is found that the covalent bonding of carbon and vanadium is mainly contributed by 2p(z) orbital of carbon and partially by the 3d like orbitals. For vanadium dimer, the stable configuration is found to be perpendicular dimer situated on the center of the hexagon. This stable vanadium dimer configuration which has not been reported in the previous works has shown enhancement of magnetic moment per unit cell compared to an isolated dimer. The PDOS computed shows similar proportion in terms of orbital contribution as the in the case of a single vanadium atom. Moreover, vanadium dimer bond length for the favored configuration after relaxation is the same as the experimental value of isolated dimer's bond length indicating that perpendicular chain might be possible on graphene sheet. Thus, this study reveals that the vanadium atoms adsorbed graphene system is metallic and magnetic.