Fabrication and scintillation properties of Pr:Lu3Al5O12 transparent ceramics from co-precipitated nanopowders

Sintering aids may seriously deteriorate the luminescence properties of the ceramics especially for scintillators. In this work, 0.25 at%Pr:Lu3Al5O12 transparent ceramics were prepared from the co-precipitated nanopowders without any sintering aids. Ammonium hydrogen carbonate was used as precipitant and the influences of precipitant to metal ions molar ratio on nanopowders and ceramics were investigated. Excessive or insufficient precipitant will worsen the phase-purity and dispersity of the nanopowders. The nonuniform dissolution of the Lu and Al precipitants in the titration and washing process, which results in the nonstoichiometry of Al excess in the ceramics and deteriorates the optical quality. After optimizing the ratio of Lu/Al in raw powders, Pr:Lu3Al5O12 ceramics with the in-line transmittance above 80% in the visible band were obtained. The light yield is 7086 Ph/MeV and the energy resolution is 16.9% which is inferior to that of the good Pr:Lu3Al5O12 crystal. The low valent cation impurities in the raw material increase the concentration of Pr4+ and diminish the light yield. (C) 2019 Elsevier B.V. All rights reserved.