STM STUDIES OF REAL AND QUASI-PERFECT SILVER SINGLE-CRYSTAL SURFACES USED IN ELECTROCHEMICAL EXPERIMENTS

Real and quasi-perfect silver single crystal surfaces, which have been used intensively in different electrochemical investigations, are studied by STM to determine the surface profile on an atomic level. The measurements were carried out on chemically polished macroelectrodes and electrolytically grown microelectrodes in contact with air as well as under potentially controlled electrochemical conditions. The real macroelectrodes show a much higher surface corrugation than the quasi-perfect microelectrodes which have large atomically flat terraces separated by monoatomic steps. The possibility to observe the dynamics of monoatomic steps under anodic and cathodic polarization conditions on quasi-perfect single crystal surfaces is demonstrated. Nucleation and crystal growth processes are observed by means of in situ STM investigations of lead electrodeposition on Ag(111) macroelectrodes. The results demonstrate the possibility to study fundamentally the initial steps of electrocrystallization by in situ STM under electrochemical well-defined conditions.