多晶铈掺杂硅酸镥闪烁陶瓷的制备和发光性能

Fabrication and Luminescent Property of Polycrystalline Cerium-doped Lutetium Oxyorthsilicate Scintillation Ceramics

本工作对铈离子掺杂多晶硅酸镥(LSO:Ce)闪烁材料的制备方法进行了系统研究。将LSO:Ce前驱体溶胶喷雾干燥后得到了球形LSO:Ce前驱粉体,该前驱粉体在1000℃和1100℃的温度下煅烧后分别得到了不同晶型的的单相LSO:Ce球形粉体。显微结构观察显示:粉体颗粒的平均直径约为2μm,是由几十纳米大小的LSO:Ce纳米晶粒堆积而成。A型球形LSO:Ce粉体经1200℃/80MPa的放电等离子体烧结(SPS)后获得了平均晶粒尺寸为1.3μm,相对密度高达99.7%的LSO:Ce闪烁陶瓷。由A型球形LSO:Ce粉体压制的素坯在1650℃的空气气氛下烧结4 h后可获得相对密度达98.6%,平均晶粒尺寸为1.6μm的LSO:Ce陶瓷。该陶瓷经1650℃/150 MPa的热等静压(HIP)处理1 h后,获得了相对密度为99.9%的半透明LSO:Ce闪烁陶瓷,其平均晶粒尺寸为1.7μm,晶界干净。该LSO:Ce陶瓷的光产额可达28600 photons/MeV,发光衰减时间为25 ns。

Fabrication processing of cerium-doped lutetium oxyorthsilicate （Lu2SiO5：Ce3＋, LSO：Ce） scintillation materials was systematically investigated in this article. Spherical LSO：Ce precursor powder was fabricated through spray drying from the synthetic LSO：Ce precursor sol. Single-phased LSO：Ce spherical powders with A-type and B-type crystal structure were achieved under the calcining temperature of 1000℃ and 1100℃ starting from the spherical LSO：Ce precursor powder, respectively. The LSO：Ce powders with the diameter of about 2 μm are solid spherical granules, which are assembled from a set of nano-sized grains. The LSO：Ce ceramics with the average grain size of 1.3 μm were sintered by spark plasma sintering （SPS） under sintering temperature of 1200℃ and the applied pressure of 80 MPa starting from fabricated A-type LSO：Ce spherical powder. Relative density of the sintered LSO：Ce ceramics can be attained to 99.7%. The pressureless sintered ceramics with relative density of 98.6% was obtained through pressureless sintering at 1650℃ for 4 h in air starting from the green compact dry-pressured from an A-type LSO：Ce spherical powder. The average grain size of the pressureless sintered ceramics is 1.6 μm. After HIPing at 1650℃ under an argon atmosphere for 1 h, a translucent LSO：Ce ceramics with clear grain boundary was achieved. The relative density of the HIPed ceramics is 99.9% and its average grain size is 1.7 μm. The light yield of the HIPed LSO：Ce ceramics reaches 28600 photons/MeV and its luminescence decay time is 25 ns.