摘要
采用自蔓延燃烧法制备了不同镨掺杂浓度的12CaO·7Al_2O_3∶Pr^(3+)(C12A7∶Pr^(3+))X射线影像存储荧光粉。在232 nm激发下,发现Pr^(3+)掺杂摩尔分数为0.3%的荧光粉位于486 nm的蓝光发射峰呈现最大的发光强度。对C12A7∶0.3%Pr^(3+)样品进行真空热处理后,C12A7笼中的O2-基团数量减少,同时类F+色心的空笼子的数量增多,导致陷阱数目增加和光激励发光强度增大。热释发光实验表明:C12A7∶0.3%Pr^(3+)样品中存在两个深陷阱,陷阱深度分别约为0.69 e V和0.80 e V;经过真空热处理后的C12A7∶0.3%Pr^(3+)荧光粉,陷阱深度变深,陷阱数目增多,光存储性能变好。当吸收的X射线剂量为5.2 Gy时,可以实现分辨率较高的X射线成像。实验结果表明,镨掺杂C12A7荧光粉在计算机X射线摄影领域有潜在的应用前景。
X-ray storage phosphors 12CaO0x0E0xFF瘙0x01簚0x0F7Al 2O 3 ∶Pr 3＋ （C12A7 ∶Pr 3＋ ） with different doping concentrations were synthesized by a combustion method. For C12A7 ∶0.3%Pr 3＋ phosphor, the strongest intensity of the emission peak at 486 nm, originating from 3P 0- 3H 4 transition of Pr 3＋ , can be obtained upon 232 nm excititation. After the annealing in vacuum, the number of encaged O 2- anions decreased, while the amount of empty cages increased. Thus, it led to the increased number of traps and the enhanced photo-stimulable luminescence（PSL）. The thermoluminescence（TL） analysis showed that there existed two deep traps in the phosphors and the trap depths were ~0.69 and ~0.80 eV, respectively. In particular, the annealing in vacuum led to the deeper trap depths, the increased number of traps and the improved storage properties. Upon X-ray irradiation（applied dose： 5.2 Gy）, a blue image with high resolution was obtained by 808 nm stimulation. Our results suggested that the C12A7 ∶Pr 3＋ phosphors have potential application in the field of computed radiography.
作者
闫宏
宋婷
张猛
李胜男
杨健
刘春光
祝汉成
严端廷
徐长山
刘玉学
YAN Hong;SONG Ting;ZHANG Meng;LI Sheng-nan;YANG Jian;LIU Chun-guang;ZHU Han-cheng;YAN Duan-ting;XU Chang-shan;LIU Yu-xue ＊(School of Physics,Northeast Normal University,Changchun 130024,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2018年第7期895-902,共8页
Chinese Journal of Luminescence
基金
国家自然科学基金(11674050,11374047,11604044)资助项目
关键词
光致发光
荧光粉
稀土离子
热释发光
photoluminescence
phosphor
rare earth ion
thermoluminescence
