Corrosion and electrodissolution studies of cobalt and copper thin films with the quartz crystal microbalance and microelectrodes

The electrodissolution and corrosion of cobalt was studied in 0.1 N H₂SO₄ with a rotating disk electrode (RDE), microband electrodes (MBE), and the quartz crystal microbalance (QCM). The corrosion rates obtained by voltammetry were very close to those obtained with the QCM. Copper electrodissolution in 0.1 N HCl revealed that spherical diffusion enhanced the mass-transport rate at a Cu microdisk electrode and gave electrodissolution rates comparable to a RDE at high rotation speeds. Corrosion of Cu films on a QCM in oxygenated 0.1 N HCl was constant as a function of film thickness with rates up to 0.06 nm/s.