ADSORPTION AND FILM GROWTH OF C-60 ON THE GAAS(001) 2X6 SURFACE BY MOLECULAR-BEAM EPITAXY

Field ion scanning tunneling microscopy was employed to investigate C- 60 film growth on a GaAs(001)-2x6 surface prepared by molecular-beam e pitaxy. The corrugated potential of the 2x6 substrate forces the first monolayer structure to be strongly modified, resulting in formation o f a ''double-chain'' commensurate structure. A stronger interaction be tween C-60 and Ga versus C-60 and As was observed. This interaction of C-60 and the substrate, however, is limited for two to three monolaye rs at the interface and the competing intermolecular interaction gover ns the three-dimensional growth of multiple-layer C-60 crystalline fil m of the (111) orientation with a high density of screw dislocations.