▎ 摘 要
The interaction of Ag atoms with graphene moire on Rh(111) was studied by scanning tunneling microscopy. Upon adsorption at 15 K, the Ag atoms existed mainly as monomers at specific sites in the moire unit cell because thermal diffusion was suppressed. The Ag atoms exhibited a dI/dV peak at similar to 0.5 V above the Fermi level, which was assigned to Ag(5s)-C(2pz) anti-bonding state. At elevated temperature, the Ag adatoms were thermally activated to diffuse and form clusters, wherein the activation barrier depended on the moire periodicity. Furthermore, migration was induced by injecting tunneling electrons into the anti-bonding state. This work provides atomic-scale insight into the aggregation process of metal adatoms on metal-supported graphene.