A comparative study of the plasmonic properties of graphene on lattice-matched and lattice-mismatched Ni surfaces

We present an angle-resolved electron-energy-loss study of the graphene/Ni(110) system. The dispersion curve of the π plasmon, compared with that obtained for graphene synthesized on the Ni(111) surface, shows that in both systems the nature of the oscillating charge at the interface is confined in a two-dimensional layer, but in the case of graphene grown on Ni(110) the interaction with the substrate is weaker. We assign this behavior to a weaker graphene-nickel hybridization in the case of Ni(110), due to the lack of long range matching between the two-dimensional lattices of graphene and nickel.