IN-SITU ELECTROCHEMICAL ATOMIC-FORCE MICR OSCOPY STUDIES OF NUCLEATION OF SINGLE NUCLEUS ON MICROELECTRODES

The electrochemical nucleation and growth of silver single nucleus on glassy carbon microelectrode have been monitored in-situ with electroc hemical atomic force microscopy (ECAFM) at different stages. The AFM r esults show that the silver single nucleus forms at the edge of the gl assy carbon and grows to form a crystallite with (100) facet preferent ially dominated. It is confirmed that the nucleation process strongly relies on the condition of glassy carbon substrate. Multiple nuclei ar e formed on the substrate with nucleation history but single nucleus c an be achieved on the same substrate after the application of a specia l ''purging'' method. The work is the first example for the real time observation of nucleation and growth of a single nucleus on a microele ctrode and for the application of ECAFM to the studies of microelectro de systems. Comparison of the work with previous ex-situ measurements are given. The work also demonstrates a possible way to obtain a singl e crystal microelectrode which could be valuable for various purposes.