Effect of annealing temperature on optical properties of Erbium doped Y₂Zr₂O₇ transparent ceramics

Through the vacuum sintering method, Erbium-doped Y2Zr2O7 transparent ceramics were successfully fabricated. The obtained ceramics were annealed at different temperatures and the relationship between annealing temperature and sample structure was investigated to reveal the effect of oxygen vacancy. Y1.98Er0.02Zr2O7 ceramics annealed at 800( ?)C starts to be transparent and when added up to 900 C-?, samples show the highest transmittance over 76% in the near-infrared (NIR) region. Then the transmittance gradually decreased to 71% with the increase of annealing temperature. XRD and SEM measurements were performed to characterize the crystal structure and microstructure of Er3+: Y2Zr2O7 as-prepared powders and ceramics. The excitation spectra display that Y1.98Er0.02Zr2O7 ceramics can be effectively excited by 382 nm. When the annealing temperature exceeds 700( ?)C, two strong green emission bands and one red emission band can be observed in both up -conversion (UC) and down-conversion (DC) fluorescence spectra. Our results suggest that annealing tempera-ture has a great impact on the structure and optical properties of Er3+: Y2Zr2O7 ceramics, which is significant for fabricating ceramics with better optical properties.