THERMOCHEMICAL REDUCTION OF PR3-DOPED YTTRIA-STABILIZED ZIRCONIA()

Thermochemical reduction (TCR) up to 1900 K of Pr3+-doped yttria-stabi lized zirconia single crystals has been studied using optical techniqu es. Ln contrast to undoped samples, only one absorption band peaking a t similar to 375 nm was observed in reduced samples. Excitation experi ments show that the 4f5d interconfigurational band of Pr3+ overlaps th e excitation band responsible for the intrinsic luminescence. After TC R the 4f5d band shifts to higher energies. Both the appearance of the 375 nm absorption band and the shift of the Pr3+ 4f5d excitation band are related to oxygen vacancy formation after TCR.