Quasi-freestanding graphene on Ni(110): A graphene/metal contact with suppressed interface states

Graphene/Ni(110) has been studied by time-resolved X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure. The C 1s core level shows a splitting typical of periodically rippled interfaces. The analysis of the C K-edge reveals that the interface states previously observed for graphene/Ni(111) are suppressed in graphene/Ni(110). This suppression is due to the reduced hybridization of the Dirac-cone electrons in graphene with the d-bands of the (110)-oriented nickel contacts. Our results show that, contrary to commensurate growth of graphene on Ni(111), epitaxially grown graphene on Ni(110) behaves as a quasi-freestanding sheet, as the lattice mismatch gives rise to a moiré reconstruction.