Luminescence of Eu³⁺ ions in nanocrystalline zirconia

Zirconia doped with 1 mol% Eu³⁺ and annealed at 600, 800 and 1000°C and zirconia doped with 1 mol%, 3 mol%, 5 mol% Eu³⁺ and annealed at 800°C were prepared by co-precipitation method; luminescence of Eu³⁺ ions was investigated under 394 nm excitation, and the emission of ⁵D₀ → ⁷F₂ was peaked at 604 nm in zirconia annealed at 600 and 800°C, however, peaked at 610 nm in the sample annealed at 1000°C. By studying Ω₂ of ⁵D₀ → ⁷F₂, the authors found that Ω₂ increased with increasing annealing temperature. When monitored with 604 nm, the authors found that the contribution of population of ⁵L₆ level to the luminescence of ⁵D₀ → ⁷F₂ increased with increasing annealing temperature. By investigating the luminescence in the samples doped with 1 mol%, 3 mol% and 5 mol% Eu³⁺ ions, we found that the emission of ⁵D₀ → ⁷F₁ transition for the sample doped with 3 mol% Eu³⁺ ions was a broad band peaked at 597 nm.