Scanning tunneling microscopy study of molecular growth structures of Gd@C82 on Cu(111)

摘要

The coverage and temperature-dependent nucleation behaviors of the Gd@C82 metallofullerenes on Cu(111) have been studied by low-temperature scanning tunneling microscopy (LT-STM) in detail.Upon molecular deposition at low temperature,Gd@C82 molecules preferentially decorate the steps and nucleate into single layer islands with increasing coverage.Further annealing treatment leads some of the Gd@C82 molecules to assemble into bright and dim patches,which are correlated to the adsorption induced substrate reconstruction.Upon sufficient thermal activation,Gd@C82 molecules sink into the Cu(111) surface one-copper-layer-deep,forming hexagonal close-packed molecular islands with intra-molecular details observed as striped patterns.By considering the commensurability between the Gd@C82 nearest-neighbor distance and the lattice of the underlying Cu(111),we clearly identified two kinds of in-plane molecular arrangements as ((√)19 × (√)19)R23.4° and ((√)19 × (√)19)R36.6° with respect to Cu(111).Within the assembled Gd@C82 molecular,island molecules with dim-bright contrast are spatially distributed,which may be modulated by the preexisted species on Cu(111).