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 zirconium dioxid e, stabilized in the cubic phase by the addition of Y2O3 in two differ ent concentrations ( 12 and 24 mol%). Production yield and thermal sta bility confirm the attribution of the 375 nm optical absorption band t o the defect responsible for the EPR T-signal. Deviations from a rando m distribution of the stoichiometric oxygen vacancies are evidenced. T hese results agree with the existence of ordering processes in the vac ancy system, as predicted by recent structural models.