Tuning the magnetic and transport property of graphene with Ti atom and cluster

Atomic structure of Ti and Ti4 cluster on the surface of graphene are studied by the density functional theory and nonequilibrium Green’s function formalism. The most stable configurations for Ti and Ti4 adsorbed on the graphene surface are investigated, and the binding energies corresponding to the configurations are calculated. We found that the Ti4 clusters can strongly interact with pristine graphene surface, and the interaction can be further enhanced when structural vacancies are introduced onto the graphene surface. Electronic properties of metal/graphene composites are also presented to show their highly spin polarized behaviors. The transport properties of systems are dependent on the applied bias voltage. Our results also indicate that the Ti4/graphene composite is a simple and typical model to study the interactive effects of metal clusters absorbed on graphene. The results of this work could help to design novel devices such as nanoelectrodes and magnetic sensors based on graphene.