REACTIVITY OF THE OXIDE-GROWTH PROCESS ON ZR METAL IN AQUEOUS POTASSIUM-IODIDE AND OTHER ALKALI-HALIDE SOLUTIONS

The kinetics of growth of an oxide film on Zr electrode under open cir cuit conditions in Kl solutions were investigated using potential and impedance measurements. The effect of some parameters such as surface pre-treatment, concentration and salt type, including alkali halide an ions, on the reactivity of the oxide growth process were studied. In a ll cases the potential, capacitance and resistance were followed with time, and the oxide film was found to thicken continuously. The iodide ion is assumed to participate in enhancing the formation of species w hich inhibits partially the growth of oxide film on Zr surface. The im pedance diagrams of the oxide film/electrolyte interface is an almost capacitative one, with an impeded charge transfer reaction.