Electrochemical and in situ AFM studies of cadmium electrodeposition from an aqueous 0.1 M CdSO4 solution have been carried out in the case of (100) n-type silicon single crystal. The mechanisms related to the initial stages of the nucleation and growth mechanism of cadmium have been studied as a function of different potential steps. Within appropriate potential ranges the initial deposition kinetics corresponded to a model including progressive nucleation and diffusion controlled cluster growth. Nucleation rate and the number of atoms in the critical nucleus were determined from the analysis of current transients at different overpotentials. A Ncrit-value of 14 ± 1 atoms was determined in the following potential range: –9 mV = ? = –11 mV. The response of the system at different waiting times at the equilibrium potential was also investigated.
