▎ 摘　　要

The coherence of graphene layers on Ru(0001) over extended distances has been employed to identify fcc and hcp regions of the associated moire superstructure. These findings can be used as a straightforward method to discriminate between fcc and hcp hollow sites of Ru(0001). Our approach thereby makes use of the "magnifying lens" characteristics of the graphene/Ru(0001) overlayer and its coherence across several monatomic steps of the substrate. We demonstrate that the individual regions of the graphene/Ru(0001) overlayer exhibit pronounced variations in interaction strengths with deposited metal atoms. Specifically, Pt clusters have been grown at 140-180 K and they are found to organize in a well-ordered periodic array defined by the moire superlattice. Their preferred location within the graphene/Ru(0001) moire unit cell is identified to be the fcc region. (C) 2009 American Institute of Physics. [doi:10.1063/1.3246166]