γ射线辐照处理SrAl_2O_4…Eu^(2+),Dy^(3+)荧光粉的长余辉性能

Long Afterglow Characteristics ofγ-Ray Irradiated SrAl_2O_4…Eu^(2+),Dy^(3+) Phosphor

采用γ射线对SrAl_2O_4…Eu^(2+),Dy^(3+)长余辉荧光材料进行辐照处理,研究样品经辐照后的长余辉性能。用60 Co~γ射线源照射固相合成的SrAl_2O_4…Eu^(2+),Dy^(3+)长余辉荧光材料样品,累积辐照剂量为100kGy。利用X射线衍射仪(XRD)、拉曼光谱仪、紫外可见分光光度计、荧光分光光度计及热释光(TL)光谱仪对辐照前后样品的晶体结构、光吸收特性、余辉及热释光特性进行了研究。结果表明:辐照后样品的晶胞体积减小,氧空位的浓度增加;由于辐照使样品中引入更多的缺陷,其吸收光谱的强度提高。辐照后样品的余辉寿命延长,余辉光谱强度增加;热释光强度增加,且光谱向高温方向偏移,经计算得到辐照后样品中陷阱能级深度增加0.0039eV,表明辐照影响了样品中陷阱能级分布且增加了样品中的深能级陷阱数目。

To investigate the long afterglow properties of the samples,long persistence phosphors of SrAl2O4：Eu^2＋,Dy^3＋ are successfully synthesized and the samples are irradiated by irradiation,which is from the ^60Co~γsource and whose dose is accumulated to 100 kGy.The influence of irradiation on the properties of these two kinds of phosphors is studied by comparing crystal structure,optical adsorption properties,decay curve and thermoluminescence（TL）characteristics of unirradiated and irradiated samples.X-ray diffraction（XRD）,Raman spectrometer,ultraviolet visible spectrophotometer,fluorescence spectrophotometer and thermoluminescence spectrometer are used to investigate these properties.Conclusions from the present work can be briefly summarized as follows.In irradiated samples,the unit cell volume decreases and the concentration of oxygen vacancies increases after irradiation.The absorption intensity of irradiated samples rises because of more irradiation-induced defects introduced.The decay time is prolonged and the initial brightness is promoted after irradiation.Thermoluminescence studies reveal that thermoluminescence glow peak of irradiated sample shifts towards higher temperature and its intensity is improved greatly.It is calculated that the depth of traps increases 0.0039 eV after irradiation,which demonstrates that the irradiation not only affects the traps′distribution but also increases the number of deeper traps.