论文部分内容阅读
Due to the soft nature of epitaxial graphene and the lattice mismatch between graphene and metal substrates periodic moiré patterns can be formed.A graphene/metal template,moiré template,can be used to grow dispersed metal nano-clusters with controllable size and shape,metal clusters with large size and metal layers,or ordered functional molecular layers.However,how intrinsic properties of metal atoms(or functional molecules)and the moiré template infuence the selective adsorption and the growth mode of metal clusters and the molecules is still open to debate.A general rule,predicting the morphology of metal nano-clusters and molecules on a G/metal surface,important to guide experimenters,is still missing.Using frst-principles calculations combined with scanning tunneling microscopy experiments,we investigated the adsorption confgurations,electronic structures and the corresponding growth mechanism of several transition metal(TM)atoms and two kinds of molecules on a graphene/Ru(0001)moiré template(G/Ru(0001))at low coverage.For transition metal atoms,we fnd that both the unoccupied d orbital of the TM atoms and the strong sp3 hybridization of carbon atoms in the fcc region of G/Ru(0001)determine the growth mode because of the strong interactions.For molecules,due to the weak interaction between molecules and the substrate,the selective adsorption behavior is determined by the lateral dipole interactions.The simulations agree well with the experimental observations.Moreover,it also provides guidance for the selection of suitable metal atoms or molecules to form ordered dispersed structures on similar templates.