NH₄NO₃水溶液におけるジルコニウムの不働態皮膜の成長

抄録

Kinetics of the growth of passive film on a zirconium anode was investigated in an ammonium nitrate solution by using various electrochemical measurements.
Firstly, the potentiostatic anodic current was found to decay with time in a manner predicted with the so-called logarithmic rate law. However, since the same current-time relation also obeyed the inverse logarithmic rate law, no definite conclusion was obtained about which of the five mechanisms ever proposed was the most reasonable to explain the above potentiostatic polarization behaviours. From the results of the simultaneous measurements of the galvanostatic polarization characteristics and the A. C. capacitance, it was found that the establishment of high electric field across the passive film was essential for the growth of the passive film. The latter observation supports the so-called high field ionic conduction mechanism which was proposed by Mott and Cabrera.