Photographic Evidence of Delamination of Two‐Layer Structure of Anodic Oxide Films on Tantalum Formed in Electrolytes Containing Phosphate

Abstract

Direct photographic evidence of delamination of the two‐layer film structure for anodic tantalum oxide films formed in phosphate‐containing electrolytes has been discovered in scanning electron microscopy photomicrographs of flaws in the anodic oxide. The amorphous dielectric oxide, whose bi‐layer structure was suggested by Vermilyea et al., appears to have been displaced from the site of crystalline oxide growth and to have undergone layer delamination as a result of the large mechanical stresses present.