Noise Energy Adopted to Understand Nickel Electroplating Process

Electrochemical noise (EN) coupled with chronoamperometry and cyclic voltammetry techniques were adopted to investigate the influences of substrate, temperature (T), current density (D K) and Ni2+ concentration (c i) on nickel electroplating process. The results show that the noise energy (E D) is weakly affected by c i as far as the concentration range concerned, and is limitedly influenced by the substrate, D K and T. The influence of D K on E D is achieved by its effect on the nucleation behavior of the initial deposit monolayer (the D K-depended nucleation behavior). E D mainly reflects the foreign work consumed in the procedure of formation of the initial deposit monolayer but not that in its subsequent growth process, and E D may be used as an index of EN to characterize the difficulty level of localized attacks (such as the formation of initial monolayer of crystallites and pits) for a defined area.