Fabrication of transparent Ce: LuAG ceramics by a solid-state reaction method

Lu2O3 powders with an average particle size of about 40nm were produced by a precipitation methed using Lu (NO3)(3) and NH4HCO3 as starting materials. The precipitation precursor is amorphous and transforms into pure LU2O3 phase by calcining at 600 degrees C for 2h. The resultant LU2O3, Al2O3 and CeO2 powders were mixed by ball milling, and then sintered into a fully transparent Ce:LuAG ceramic body by vacuum sintering at 1760 degrees C for 10h and annealed at 1450 degrees C for 20h. The resultant transparent ceramic has a uniform microstructure with an average grain size of about 4 mu m. The polished Ce:LuAG ceramic disk with 1.2mm thickness is highly transparent. The transmittance in the visible region reaches 56%, which is 72% of the theoretical value. The emission spectrum at 470 similar to 650nm with the double peak structure (517nm and 552nm) excited by X-ray is the characteristic spectrum of Ce3+ due to the 5d-4f transition, is consistent with that of LuAG:Ce single crystals, well coupled with the silicon photodiodes and satisfies the property requirements of a scintillator. Ce:LuAG transparent ceramics is a promising scintillating material.