Effects of sintering temperature on the microstructure and luminescence of LuAG:Pr ceramics

Highlights: • Effects of sintering temperature on LuAG:Pr. • Amorphous phase in ceramics is detrimental to luminescence. • Synergism between defects and Pr³⁺ luminescence. -- Abstract: The effects of the sintering temperature on the microsctruture and luminescence of Lu₃Al₅O₁₂:Pr (LuAG:Pr) ceramics was investigated by density, X-ray diffraction (XRD), scanning electron microscopy (SEM), grain size, attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR), photoluminescence (PL), radioluminescence (RL), and thermoluminescence (TL) measurements. A Czochralski-grown single crystal was used as reference. The increase of the sintering temperature promoted progressive structural modifications toward the characteristics of the single crystal. The presence of an amorphous phase was strongly detrimental to the luminescence of LuAG:Pr, with its elimination leading to enhanced RL and reduced TL emission. Evidence of synergism between the F-related defects and the Pr³⁺ 4f - 4f and 4f - 5d transitions was also found with the presence of these defects being detrimental to the 5d - 4f scintillation.