The Effect of the Deposition Conditions on the Structure, Composition and Morphology of Electrodeposited Cobalt Materials

The surface morphology, microstructure and thickness of electrodeposited cobalt films on gold was studied using scanning electron microscopy with chemical analysis, cycling voltammetry and extended X-ray absorption fine structure. The results show that all the details of the electrodeposition conditions such as solution (chloride, nitrate and sulfate bath), concentration, time of deposition and temperature substantially influence film growth. Deposition in nitrate solution results in different morphology and atomic structure than in sulfate or chloride solutions. Further studies, using CoCl2, showed that the growth of the cobalt layer follows a potential law with increasing concentrations or time of deposition. In both cases, similar morphologies are obtained. The influence of bath temperature on cobalt deposition was also investigated, showing an exponential increase of cobalt layer thickness with temperature. Furthermore, the opportunity to synthesize nanostructured Co films with tailored lattice parameters are discussed.