Evidence and Consequences of Ce4+ in LYSO:Ce, Ca and LYSO:Ce, Mg Single Crystals for Medical Imaging Applications
Evidence and Consequences of Ce4+ in LYSO:Ce, Ca and LYSO:Ce, Mg Single Crystals for Medical Imaging Applications
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DOI：
10.1109/tns.2013.2269700
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发表时间：
2013-08-01
影响因子：
1.8
通讯作者：
Ouspenski, V.
中科院分区：
文献类型：
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作者：
Blahuta, S.;Bessiere, A.;Ouspenski, V.
采用提拉法制备了Ca ~（2+）和Mg ~（2+）共掺的Lu_2（1-x）Y_2xSiO_5：Ce（10at%Y）单晶。结果表明，共掺杂导致显着改善的闪烁性能。X射线激发后的余辉在20 ms后降低到200 ppm，并且在Cs-137-662 keV激发下，光产额从28，000 ph/MeV增加到34，000 ph/MeV。使用X射线吸收近边光谱（XANES）来证明在共掺杂晶体中，Ce离子的显著部分稳定在Ce 4+氧化态。提出了一种新的闪烁机制。
Lu2(1-x)Y2xSiO5:Ce (10 at% Y) single crystals co-doped with Ca2+ and Mg2+ were prepared by the Czochralski technique. It is shown that co-doping leads to significant improvements of the scintillation performances. Afterglow following X-ray excitation is reduced down to 200 ppm after 20 ms and light yield is increased from 28,000 ph/MeV up to 34,000 ph/MeV under Cs-137-662 keV excitation. X-ray Absorption Near Edge Spectroscopy (XANES) was used to demonstrate that a significant part of the Ce ions are stabilized in the Ce4+ oxidation state in co-doped crystals. A new scintillation mechanism involving Ce4+ is proposed.