Potentiodynamic behavior of as-grown and annealed porous anodic alumina films: Current overshoots and oscillations in transients

This work presents the results of investigation of the behavior of as-grown and annealed in air at 200 °C in phosphoric acid alumina films during the first and repeated polarizations in the barrier-type anodizing solution under potential sweep conditions. The current overshoots in transients in the annealed porous alumina films at the second potential sweep were found to be dependent on the magnitude of current, which was interrupted at the first sweep. Assumingly these overshoots were caused by an abrupt drop in the mobility of electrons injected from electrolyte in alumina film upon annealing. These experiments also revealed the current oscillations, following the current overshoot, in the voltammograms of repeated potential sweeps and the origin of this phenomenon was considered.

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