Microstructure evolution of yttria-stabilized cubic zirconia, ZrO2-13mol%Y2O3, was investigated through transmission electron microscopy under irradiation with electrons and/or ions. Anomalous formation of large defect clusters was found under electron irradiation subsequent to ion irradiation, such as 300keV O+, 100keV He+ and 4keV Ar+ ions. Such defect clusters were not formed solely with ion irradiation. The extended defect clusters possess strong black/black lobes contrast, and were observed preferentially around a focused electron beam at or near dislocations at temperature less than 520K. The defect clusters were transformed into dislocation network when they reached a critical diameter of some 1.0 to 1.5μm, and processes of nucleation, growth and transformation were repeated under electron irradiation. The defect clusters were assumed to be O platelets induced through selective displacements of O ions in yttria-stabilized cubic zirconia with electron irradiation. An important role of the accumulation of electric charges due to the selective displacements in yttria-stabilized cubic zirconia was also discussed.

Radiation-Induced Defect Clusters in Fully Stabilized Zirconia Irradiated with Ions and/or Electrons. K.Yasuda, C.Kinoshita, S.Matsumura, A.I.Ryazanov: Journal of Nuclear Materials, 2003, 319, 74-80