多晶铈掺杂硅酸镥闪烁陶瓷的制备和发光性能

doi:10.15541/jim20170322

摘要/Abstract

摘要：

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2 µm, 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1.3 µm, 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1.6 μm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1.7 μm, 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。

关键词: 硅酸镥, 制备, SPS, HIP, 闪烁陶瓷

Abstract:

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.

Key words: lutetium oxyorthosilicate, fabrication, SPS, HIP, scintillation ceramics

中图分类号:

TQ174

范灵聪, 施鹰, 谢建军. 多晶铈掺杂硅酸镥闪烁陶瓷的制备和发光性能[J]. 无机材料学报, 2018, 33(2): 237-244.

FAN Ling-Cong, SHI Ying, XIE Jian-Jun. Fabrication and Luminescent Property of Polycrystalline Cerium-doped Lutetium Oxyorthsilicate Scintillation Ceramics[J]. Journal of Inorganic Materials, 2018, 33(2): 237-244.

图/表 11

图1 喷雾干燥后LSO:Ce前驱粉体的TG-DSC曲线

Fig. 1 TG-DSC curves of the LSO:Ce precursor derived from spray drying

图2 在(a) 1000和(b) 1100℃下煅烧的粉体的XRD图谱

Fig. 2 XRD patterns of the precursors calcined at (a) 1000℃ and (b) 1100℃

图3 喷雾干燥法制备的前驱体(a, b)及在(c)1000、(d)1100、(e)1200和(f)1300℃煅烧后粉体的SEM照片

Fig. 3 SEM images of the precursors (a, b) and precursors calcined at (c) 1000℃, (d) 1100℃, (e) 1200℃ and (f) 1300℃

图4 以微米级球形粉体在(a)1150、(b)1200、(c)1250、(d)1300和(e)1350℃温度下SPS烧结5 min的LSO:Ce陶瓷断面SEM照片

Fig. 4 SEM images of fracture surfaces of LSO:Ce ceramics SPS-sintered at (a) 1150℃, (b) 1200℃, (c) 1250℃, (d) 1300℃ and (e) 1350℃ for 5 min from micrometer-sized spherical powders

图5 SPS烧结温度对LSO:Ce陶瓷晶粒尺寸和气孔率的影响

Fig. 5 Dependence of the grain size and the porosity of SPS- sintered LSO:Ce ceramics on the sintering temperature

图6 LSO:Ce陶瓷在(a)HIP前和(b)HIP后的抛光表面形貌

Fig. 6 Polished surface morphologies of LSO:Ce ceramics (a) before and (b) after HIPing

图7 热等静压LSO:Ce陶瓷的光致发射和激发谱

Fig. 7 PL and PLE spectra of the HIPed LSO:Ce ceramics

图8 热等静压LSO:Ce陶瓷在阴极射线激发下的发射光谱, 插图为相应的粗晶粒区和细晶粒区形貌

Fig. 8 CL spectra of the HIPed LSO:Ce ceramics Insets are the morphologies of the respective coarse-grained and fine- grained area

图9 热等静压LSO:Ce陶瓷的直线透过率曲线, 插图为该陶瓷的实物照片

Fig. 9 In-line transmittance curve of the HIPed LSO:Ce ceramics Inset is photograph of the HIPed ceramics

图10 热等静压LSO:Ce陶瓷和BGO单晶的137Cs能谱图

Fig. 10 137Cs spectra of the HIPed LSO:Ce ceramics and BGO single crystal

图11 热等静压LSO:Ce陶瓷的发光衰减曲线(λex=360 nm, λem=406 nm)

Fig. 11 Luminescence decay curve of the HIPed LSO:Ce ceramics (λex=360 nm, λem=406 nm)

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