Stoichiometric modulation and scintillation property characterization of Ce,Ca:LuAG ceramics

Due to the huge difference in the solubility-product constants (Ksp) between the precipitates of Lu and Al, the synthesis of lutetium aluminum garnet (Lu3Al5O12, LuAG) nanopowders by coprecipitation method is prone to Lu loss, resulting in the creation of Al2O3 secondary phase. In this work, coprecipitated (Ce0.001Ca0.0015Lu(0.9975+x%))(3)Al5O12 (x = 0, 0.9, 1.2, 1.5) nanopowders with different starting stoichiometries are synthesized and combined with vacuum pre-sintering and hot-isostatic pressing to fabricate scintillating ceramics. The effect of compensated Lu content on the phase composition, microstructure, optical properties, and scintillation performance of ceramics is analyzed. The complete elimination of the secondary phase requires an additional compensation of 1.2% of Lu, which gives the best transmittance in ceramics. When x = 1.5, excessive Lu forms Lu-Al antisite defect, leading to the decrease of both light yield and intensity of the fast scintillation component.