STM OBSERVATIONS OF THE INITIAL-STAGES OF COPPER DEPOSITION ON GOLD SINGLE-CRYSTAL ELECTRODES

Scanning tunneling microscopy has been used in situ and in real tim to follow the progress of copper electrocrystallization on Au(111). Initially deposition occurs at step edges, dislocations and defects in the substrate surface. At longer times, deposition is also observed on flat terraced regions of the surface. Typically the rate of growth of the deposit is far faster in the x and y directions than it is in the z direction. As expected, the copper deposit redissolves at potentials positive of the Nernst potential, and the surface generally returns close to the state it was in before the bulk copper deposition. However, small amounts of tenaciously held deposit sometimes remain, and these redissolve more slowly and at more positive potentials.