A study on the kinetics of Co–Ni/Cu multilayer electrodeposition in sulfate solution

Electrodeposition of the Co–Ni/Cu multilayer films was carried out in sulfate solution. Cyclic voltammetry and current transient techniques were utilized to characterize the multilayer system and to obtain the nucleation and growth mechanism. The cyclic voltammograms clearly showed that electrodeposition of cobalt–nickel alloy layer was controlled by a kinetic process, where copper ions were reduced under diffusion-controlled mechanism. In addition, the current transients revealed that nucleation mechanism was instantaneous with a typical three-dimensional growth process. The microstructure of the Co–Ni/Cu films was also changed with overpotential. In this system, the growth of multilayer films was observed as layer-by-layer structure up to −1.3 V versus SCE.