The Current‐Time Relationship during Anodic Oxide Film Growth under High Electric Field

An interpretation of current‐time transients describing anodic oxide film growth on metals is presented. When the rate of oxide film growth is controlled by ion conduction under high electric field, the classical theory of Cabrera and Mott leads to shallow curvature in plots of vs. . Such data can be linearized by using an integrated form of Cabrera and Mott's equation. The predicted form of the current transient shows decaying linearly as from which film growth parameters may be calculated. The equations distinguish sensitively between Cabrera‐Mott film growth kinetics and direct logarithmic film growth kinetics. The effects of the presence of an ohmic potential drop in the electrolyte are shown. The equations are tested in terms of anodic oxide film growth on iron and titanium.