Abstract: Sintering aids are widely used to improve the optical quality of ceramics in the preparation of transparent ceramics. However, sintering aids may deteriorate the luminescent properties of the ceramics. In this work, 0.25at%Pr:LuAG scintillation ceramics were prepared by vacuum pre-sintering combined with hot isostatic pressing.
The influences of trace SiO2 sintering aid on the optical and scintillation properties of the ceramics were studied. The results show that a small amount of SiO2 below 200 ppm (1 ppm means that addition content is 1×10–6 g/g) can effectively promote the remove of pore during hot isostatic pressing and improve the optical quality of the Pr:LuAG ceramics. Their in-line transmittance with 150 ppm SiO2 is about 77% at 400 nm. The effects of pre-sintering temperature and holding time on the optical properties of Pr:LuAG ceramics were also investigated. When completely closed pore structure is formed, further increasing the pre-sintering temperature or prolonging the holding time reduce the densifi-cation rate in the hot isostatic pressing process, which is not conducive to the remove of pores and lower the optical quality of the Pr:LuAG ceramics. In addition, trace SiO2 addition has less effect on scintillation properties of the Pr:LuAG ceramics. Adding trace SiO2 sintering aid combined with hot isostatic pressing is an effective way to prepare Pr doped garnet scintillation ceramics.
Key words: Pr:LuAG ceramics; sintering aids; optical quality; scintillation property