Luminescence properties of garnet Lu₃Al₅O₁₂:Ce nano-scale phosphors

Nano-scale Lu₃Al₅O₁₂ phosphors doped with Ce³⁺ were synthesized through co-precipitation method by using metal nitrates as the starting materials and NH₄HCO₃ solution as precipitant. Heat treatment was performed in the temperature range from 850 to 1200°C. The crystal structure, particle size and morphology of the precursor and synthesized powders at different calcinations temperature were determined by XRD and TEM. The results indicated that the cubic garnet phase of Lu₃Al₅O₁₂:Ce was obtained at 900°C. Well-dispersed Lu₃Al₅O₁₂:Ce nano-phosphors with favorable luminescence properties were obtained by calcining the precipitate precursor at 1000°C for 2 h, and the particle size increased with the sintering temperature. The optimal content of Ce³⁺ in Lu₃Al₅O₁₂ host was 0.5% (atom fraction) under UV light excitation. Translucent Lu₃Al₅O₁₂:Ce ceramics could be obtained by sintering in flowing H₂ atmosphere at 1800 °C for 6 h. The Ce³⁺ doped Lu₃Al₅O₁₂ ceramics exhibited rapid decay (ns) under X-ray excitation.