Graphene moiré structure grown on a pseudomorphic metal overlayer supported on Ru(0001)

A versatile method is demonstrated to modify graphene–metal interaction by overlaying a pseudomorphic monolayer of transition metal on the substrate metal. Using this method, sample-sized, high-quality graphene has been prepared on a pseudomorphic monolayer of Co and Pd deposited on Ru(0001) respectively, and studied by scanning tunneling microscopy, low energy electron diffraction, Auger electron spectroscopy, and density function theory calculations. Graphene develops moiré patterns on the two pseudomorphic monolayer surfaces, with a periodicity that is identical to that of graphene on Ru(0001) but completely different from graphene on Co(0001) and Pd(111). STM measurements, supported by DFT calculations, indicate that graphene on the two surfaces exhibits distinctly different corrugation from that of graphene on Ru(0001), in order of decreasing height CoML/Ru > Ru > PdML/Ru, suggesting that this method can be used to tune the interaction strength between graphene and a metal substrate.