Diffusivity of point defects in the passive film on Fe

Abstract

Diffusivity of point defects ( D 0) in the passive film formed on Fe in deaerated pH 8.5 buffer solution at ambient temperature was estimated by the Mott-Schottky analysis based on the Point Defect Model and surface charge approach assuming that donors are oxygen vacancies and/or iron interstitials. From the exponential decay of the concentration of donors with film formation potential, D 0 was calculated to be 1.69 × 10 −20 cm 2 s −1.