Effect of post-annealing in air on optical and XPS spectra of Y2O3 ceramics doped with CeO2

Yttrium oxide ceramics doped with CeO₂ (5 mol%) were prepared from nanopowders produced by the laser ablation method. The optical measurements have demonstrated that the transparency of as-sintered ceramic was markedly increased after annealing (T=1400°C) under air. XPS data revealed the presence of mixed Ce³⁺ and Ce⁴⁺ states, while oxygen defect peak decreased after annealing owing to the defect elimination during oxygen diffusion into the highly defective ceramic.