Optical absorption and luminescence studies were made of neutron-irradiated or thermochemically reduced yttria-stabilized crystals. Two absorption bands, centred at about 375 and 470nm, were observed after irradiation or reduction. The thermal stability of the bands was very different for the 2 cases. In the case of irradiated crystals, the bands disappeared during heat treatment at about 600K. In reduced crystals, they annealed out at about 1300K. This difference was attributed to interstitial-vacancy recombination in the O sub-lattice of the former crystals. Nano-indentation tests showed that the hardness and elastic modulus remained essentially unchanged after thermochemical reduction or neutron irradiation. The results confirmed that single crystals of this material were radiation-resistant, and that the radiation damage could easily be removed by annealing in air at temperatures above 600K.

Radiation Damage in Neutron-Irradiated Yttria-Stabilized Zirconia Single Crystals. B.Savoini, I.Caceres, I.Vergara, R.Gonzalez, J.E.Munoz Santiuste: Journal of Nuclear Materials, 2000, 277[2-3], 199-203