Abstract
Uniform and sustained anode potential oscillations (amplitude, 10–20V) have been observed in galvanostatic dissolution of copper in chlorate electrolyte. The oscillations occur in the current density range of 0.3–150 A/cm2. Frequency increases with current density in this range from 10−3 to 103 Hz. Increases in electrolyte temperature, acidity, and flow rate were found to result in a decrease of oscillation frequency. Large amplitude oscillations were also observed in a narrower current density range and with less cycle uniformity, in a variety of mixed electrolytes containing small concentrations of halides. The rise and fall of potential reflects an alternate growth and destruction of an adherent cuprous oxide surface layer. A model for the oscillations is proposed based on resistive switching transitions within the anode surface film.