Models for Ionic Conduction in Anodic Oxide Films

It is argued that the history effects, which are an important feature of the behavior of the high field ionic conductivity of anodic oxide films on tantalum and several other metals, are more probably due to structural effects than to a current‐driven component of dielectric polarization. The argument is developed, in particular, for films, since a knowledge of the structure of is available from recent work by Roth et al. and others. It is shown that equations can be formulated, on a phenomenological basis, which describe the experimental results for ionic conduction.