Abstract
Dielectric measurements have been used to study the distribution of the conductivity which is introduced into the anodic oxide film on tantalum by heat‐treatment in air. The temperature and frequency dependences of capacitance indicate that the conductivity distribution is exponential with position in the oxide. The combination of these dependences yields an activation energy of 0.6 ev for the conduction process. The temperature and frequency dependences of tan δ for films which have been partially reanodized after heat‐treatment also yield an activation energy of 0.6 ev.