This study determined the semiconductor character of the anodically passive films formed on zirconium in 0.5 M NaOH (pH=13.3), estimated the dopant levels in these films, and estimated the passive film thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the anodically passive films displayed n-type semiconductive characteristics, where oxygen vacancies and cation interstitials preponderated. Based on the Mott–Schottky analysis, it was shown that the calculated donor density increased with increases in formation potential. Moreover, the results indicated that the thickness of the anodically passive films increased linearly with the film formation potential.
