Defect structures and electronic properties in cubic stabilized zirconia

EPR and optical absorption measurements have been performed to detect the defects activated by X-rays in single crystals of zinconium dioxide, stabilized in the cubic phase by the addition of Y₂O₃ in two different concentrations (12 and 24 mol%). Production yield and thermal stability confirm the attribution of the 375 nm optical absorption band to the defect responsible for the EPR T-signal. Deviations from a random distribution of the stoichiometric oxygen vacancies are evidenced. These results agree with the existence of ordering processes in the vacancy system, as predicted by recent structural models.