Cation-driven electrical conductivity in Ta-doped orthorhombic zirconia ceramics

This paper is devoted to the study of electrical conductivity tantalum-doped zirconia ceramics prepared by spark plasma sintering. In this study, temperature dependence in as-prepared specimens and those previously annealed air determined compared. A semi-empirical model, which based on oxidation states cations, has been developed successfully assessed. According this, basically controlled diffusion tetravalent zirconium cations both cases, although concentration these species varies drastically with amount induced oxygen vacancies. a quite unexpected fact, since normally anionic ceramics. option forbidden here due presence substitutional pentavalent cations. Therefore, values are much lower than reported trivalent or divalent cation doped