At pH> 4.00, the electrodeposition of cobalt occurs via Co(OH)2 forming in the interface electrode solution (chemicalstage). In the cobalt electrodeposition process the interface electrode solution becomes alkaline due to the water reduction (Eq(5)). The local alkalization that occurs in the interface electrode solution can provoke the precipitation of the Co(OH)2 as showed in Pourbaix diagram (Fig. 1). The presence of cobalt hydroxide was confirmed with an electrochemistry quartz crystalmicrobalance (EQCM) technique, as done by Matsushima et al. [11].H3BO3 was added to the cobalt electrodeposition solution to avoid pH variations in the interface electrode solution. In this case,the electrodeposition of cobalt occurs directly, owing to Eq. (1) [12]. Eqs. (5)–(8) describe the electrodeposition process through formation of a cobalt hydroxide intermediate: