Role of Y Admixture in (Lu1-xYx)3Al5O12: Pr Ceramic Scintillators Free of Host Luminescence

Point defects can seriously affect the performance of scintillator materials. Therefore, the fabrication of defect-free scintillators is an exciting goal for materials scientists. By applying an advanced optical ceramic preparation process, (Lu1-xYx)(3)Al5O12 : Pr (LuYAG: Pr) ceramics free of defect-induced host luminescence are produced. Moreover, a detailed low-temperature thermoluminescence (TSL) study reveals that all TSL peak intensities and trap depths decrease in the Yadmixture. The whole phenomenology indicates that a joint effect of band-gap engineering and defect engineering works in LuYAG: Pr ceramics, as confirmed by the comparison between TSL data, radioluminescence temperature-dependence measurements, and first-principles calculations. As a consequence of material optimization, the light yield of LuYAG: Pr ceramics with 25% Yis found to be 24 400 ph/MeV with a short 1.0-mu s shaping time, which is 20% higher than the value obtained for Y-free LuAG: Pr ceramics. We close with an explanation of the role of Y that also suggests future research directions concerning other oxide scintillators.