AC impedance study of pattern formation of silver electrodeposits

Electrochemical impedance was examined in the two-dimensional growth of Ag electrodeposits to investigate the rate-determining step in the pattern formation of the aggregates. The frequency dispersions of the in-situ ac impedance during the electrodeposition demonstrated that the open-ramified growth is diffusion-limited, the dendritic growth is reaction-limited, the homogeneous growth is electric-migration-limited and the DBM (dense branching morphology) growth is both diffusion and electric-migration controlled.