MECHANISM OF IONIC CONDUCTION IN LOW ELECTRIC FIELDS IN ANODIC OXIDE FILMS OF TANTALUM FOMRED IN H3PO4.

During the anodic oxidation of Ta, the presence of a strong electric field in the Ta//2O//5 film induces the migration of tantalum and oxygen ions through the same, giving way to the formation of new oxide layers. The oxide formed has an amorphous nature and the field/current relation is i equals A multiplied by (times) exp (B. E. ) type. The field/current relation has been experimentally proven for a relatively restricted electric field range. With the aim of extending the measurements to lower fields, the authors have used sintered Ta powder, with which the effective oxidation area increases in several orders of magnitude, the current densities can diminish markedly, achieving a decrease in the electric field value present during oxidation.