INSITU SCANNING TUNNELING MICROSCOPY STUDY OF THE INITIAL-STAGES OF BULK COPPER DEPOSITION ON AU(100) - THE RIM EFFECT

In situ scanning tunneling microscopy (STM) has been used to follow the progress of copper electrocrystallization on a Au(100) substrate in the presence of crystal violet. The topography of the Au(100) surface is characterized by monoatomic high gold islands of 5-30 nm in diameter sitting on-top of flat terraces. These islands are a direct consequence of the lifting of surface reconstruction. At very early stages of bulk copper deposition, nucleation and growth start exclusively around the rim of these gold islands and also along step edges. This 'rim-nucleation' phenomenon is explained by the large number of kink sites, which exist around the gold islands and the step edges. Later, at longer time or at higher overpotential, lateral spreading of the bulk copper deposit across the substrate surface occurred. The quasi-two-dimensional growth of the copper film on a Au(100) surface, which has been observed in this study, arises through the action or influence of crystal violet, which has been added to the electrolyte solution.