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1.
《Radiation measurements》2004,38(4-6):393-396
On-line measured radiation-induced absorption spectra and their kinetics are presented for the doped PbWO4, YAlO3:Ce and CsI crystals. In the doubly doped PbWO4:Mo,Y crystals the saturation level of the induced absorption increased with Mo concentration up to 2750 ppm. With a higher concentration it again gradually decreased. Yttrium co-doping around 100 ppm improved considerably the radiation hardness of Mo-doped PbWO4. Characteristic recovery time of these crystals was about 30 min. Positive influence of Zr+4 co-doping on characteristics of a set of YAlO3:Ce samples resulted in decrease in the induced absorption intensity. The presence of very slow recovery processes was in good agreement with thermoluminescence characteristics above room temperature reported earlier. An absorption band round 420 nm appeared in as-grown CsI crystals doped with Tl, and was related to the oxygen contamination.  相似文献   

2.
YAlO3晶体中pr3+的4f2能级   总被引:1,自引:1,他引:0  
赖昌  王广川 《发光学报》2011,32(9):885-889
YAlO3∶pr3+是一种受到广泛关注的发光体系,本文根据文献中给出的YAlO3∶pr3+晶体中Pr3+的晶体场能级,从Nd3+离子的晶体场参数和Pr3+的准自由离子参数出发,采用f-shell计算软件包对pr3+的能级参数进行了研究,并对获得的参数进行了讨论.用拟合获得的参数计算了pr3+的4f2电子构型的所有能级.  相似文献   

3.
Yb3+-doped YAlO3 single crystals were grown by the Czochralski method with a radio frequency heating system. The starting melt compositions of Y1−xYbxAlO3 were varied as x=0.02, 0.1, 0.2, 0.3 and 0.45. Photo- and thermo-luminescence characteristics including emission decays were measured within 4–300 K. Very fast charge transfer luminescence of Yb3+ was found, with the typical double peak spectrum at 345 and 525 nm. At room temperature the photoluminescence and scintillation decay curves show a leading subnanosecond decay component without any additional slower processes. The high density of Yb-rich YAlO3 makes this material a promising candidate for fast scintillators.  相似文献   

4.
The present work is devoted to the investigation of transient absorption (TA) induced by a pulsed electron beam (E=250 keV) in pure and doped YAlO3 (YAP) single crystals. The nature of centers responsible for TA is discussed.  相似文献   

5.
Electron spin resonance measurements of Ce-doped YAlO3 single crystals (40–50 ppm of Ce) grown by Czochralski method from Molybdenum crucibles evidenced two kinds of Mo3+ centers. The ESR spectra of both centers were described by spin Hamiltonian with orthorhombic symmetry and an effective electron spin . The experimental g-factors as well as four magnetically nonequivalent positions found for each center support a hypothesis that Mo impurity ion is located at Al site. Under high-temperature annealing and UV irradiation the Mo centers show the change of charge state, indicating, that they are probably involved in the charge carrier capture in the energy transfer and storage processes in this scintillator material.  相似文献   

6.
We investigate the spectra and scintillation properties of Ce:YA103,Ce:Y3Al5O12,and Ce:LaA103.For Ce:YAlO3,the excitation spectrum is very similar with the absorption spectrum;for Ce:Y3Al5O12 and Ce:LaAlO3,the excitation spectra are different from the absorption spectra.Further,Ce:YAlO3 has better scintillation performance than Ce:Y3Al5O12 whereas Ce:LaAlO3 has not demonstrated scintillation performance to date.We also provide reasonable explanations for these experimental phenomena from the viewpoint of energy level structure.  相似文献   

7.
采用熔融法制备了Tb3+掺杂的Bi2O3-B2O3系统玻璃,使用激发、发射及拉曼光谱分析了光学碱度与玻璃结构及发光性能的关系,同时绘制了Tb3+、Bi3+和Bi2+的能级图。研究结果表明:Tb3+掺杂的Bi2O3-B2O3玻璃由[BO3]、[BiO3]、[BO4]及[BiO6]共同组成,且随着光学碱度由0.63增加到0.93,玻璃的结构逐渐疏松。高的光学碱度使部分Bi3+变为Bi2+,发出571 nm(2P3/2(2)2P1/2)的光,Bi3+→Tb3+的能量降低。在光学碱度及Tb3+、Bi3+和Bi2+离子的共同作用下,随着光学碱度的提高,玻璃的发光颜色由黄绿色变为白色。  相似文献   

8.
The potential of single crystals K5Li2LnF10, for applications as VUV excited phosphors has been examined. The crystals were doped with lanthanide ions (Ce3+–Nd3+) with concentrations up to 100 at%. The self-quenching of luminescence is strongly reduced in this material. Luminescence spectra in the 50,000–10,000 cm−1 range and excitation spectra in the 40,000–250,000 cm−1 spectral range have been recorded at room and low temperature. Intense visible emission has been observed for Nd3+ and Pr3+. For the Pr3+ ions strong the 1S01I6 transition has been recorded only for concentrated crystals. Efficient conversion of VUV excitation to UV–VIS emission was observed in crystals doped with 3 and 100 at% of cerium. In both cerium-activated crystals the lifetimes of fd transitions were equal to 32 ns.  相似文献   

9.
高伟  董军  王瑞博  王朝晋  郑海荣 《物理学报》2016,65(8):84205-084205
采用水热法成功制备了Er3+/Yb3+共掺杂的NaYF4和LiYF4微米晶体. 通过X射线衍射仪和环境扫描电子显微镜对样品的晶体结构及形貌进行表征. 实验结果表明: 六方相NaYF4微米晶体为棒状结构, 而四方相LiYF4微米晶体则为八面体结构. 在近红外光980 nm激发下, NaYF4:Yb3+/Er3+和LiYF4:Yb3+/Er3+ 微米晶体均展现出很强上转换荧光发射. 且NaYF4:Yb3+/Er3+微米晶体的荧光发射强度大约是LiYF4:Yb3+/Er3+微米晶体的2倍, 但红绿比明显较低. 根据荧光光谱, 并借助激光光谱学及发光动力学深入探讨基质变化及表面修饰剂乙二胺四乙二酸(EDTA)对荧光特性的影响. 实验结果发现: 影响荧光强度的主要因素是基质环境的局域对称性, 而导致不同红绿比则是由于样品表面较多的EDTA分子所引起. Er3+掺杂的NaYF4和LiYF4 微米晶体呈现出很强的绿光发射可被应用于全色显示, 荧光粉和微光电子器件中.  相似文献   

10.
刘坚  刘军芳  苏良碧  张倩  马凤凯  姜大朋  徐军 《物理学报》2016,65(5):54207-054207
通过坩埚下降法生长了系列共掺Nd,Gd:CaF2和Nd,Y:CaF2晶体, 研究了Gd3+/Y3+共掺对Nd3+光谱性能以及Nd:CaF2晶体晶胞参数的影响规律. 对于0.5 at.%Nd, x at.%Gd(x=2,5,8,10):CaF2系列晶体, 当调控Gd3+掺杂浓度为2 at.%时, 具有最大的荧光寿命499 μs; 当Gd3+掺杂浓度为5 at.%时, 具有最大的吸收截面1.47×10-20 cm2, 最大的发射截面1.9×10-20 cm2; 当Gd3+掺杂浓度为8 at.%时, 具有最佳的发射带宽29.03 nm. 对于0.6 at.%Nd, xat.%Y(x=2, 5, 8, 10):CaF2系列晶体, Y3+掺杂浓度为5 at.%时, 有最大的吸收截面2.41×10-20 cm2, 最大的发射截面3.17×10-20 cm2; 当Y3+掺杂浓度为10 at.%时, 具有最长的荧光寿命359.4 μs,并且具有最大发射带宽26 nm.  相似文献   

11.
刘红利  郝玉英  许并社 《物理学报》2013,62(10):108504-108504
采用高温固相法制备了LiSrBO3:xEu3+ 荧光粉, 并通过XRD, 红外(FITR) 和荧光光谱(PL) 等对其表征. 结果表明, LiSrBO3: Eu3+ 荧光粉可被波长为395 nm 的紫外线和466 nm 的蓝光有效激发, 且发射主波长为612 nm (Eu3+的电偶极跃迁5D07F2) 的红光. 研究了Eu3+ 掺杂浓度对LiSrBO3: Eu3+ 材料发光强度的影响, Eu3+ 掺杂浓度为6% 时样品的发射强度最大, 并且证实Eu3+ 之间的能量传递机制为电偶极子- 电偶极子相互作用. Li+, Na+, K+ 作为电荷补偿剂的引入全部导致LiSrBO3: Eu3+ 材料发射强度增强, 其中, Li+ 的引入要优于Na+ 和K+. 少量Al3+的掺杂降低了Eu3+ 所处格位的对称性, 增强了Eu3+ 的612 nm 的电偶极发射, 改善了LiSrBO3: Eu3+ 红色材料的色纯度. 关键词: 白光发光二级管 光致发光 浓度猝灭 电荷补偿剂  相似文献   

12.
王林香  庹娟  叶颖  赵海琴 《中国光学》2019,12(1):112-121
用微波高温固相法合成了Er~(3+)单掺Lu_2O_3,Li~+与Er~(3+)共掺Lu_2O_3及Li~+,Zn~(2+),Mg~(2+)掺杂Lu_2O_3∶Er~(3+)的荧光粉。实验表明金属离子Li~+、Zn~(2+)、Mg~(2+)、Er~(3+)掺杂Lu_2O_3,不影响Lu_2O_3的立方晶相。扫描电子显微镜测量表明,Li~+掺杂可以有效改善粉体的分散性和形貌,Li~+,Zn~(2+),Mg~(2+)共掺杂获得的粉体颗粒分布更加均匀,粒径范围为80~100 nm。379 nm激发下,Li~+与Er~(3+)共掺样品发光较单掺Er~(3+)样品在565 nm处的发光增强了4.5倍,而Li~+、Zn~(2+)、Mg~(2+)与Er~(3+)共掺样品较其发光增强5.3倍。980 nm激发下,Li~+与Er~(3+)共掺样品,Li~+、Zn~(2+)、Mg~(2+)与Er~(3+)共掺样品的发光分别比单掺Er~(3+)样品在565 nm处发光增强23倍与39倍,在662 nm处发光强度分别增强20倍与43倍。379 nm激发下,较单掺Er~(3+)的样品,掺杂Li~+的样品和Li~+,Zn~(2+),Mg~(2+)和Er~(3+)共掺的样品荧光寿命均有所增加,而Zn~(2+)、Er~(3+)共掺及Mg~(2+)、Er~(3+)共掺样品的荧光寿命则有所缩短。  相似文献   

13.
孟庆裕  张庆  李明  刘林峰  曲秀荣  万维龙  孙江亭 《物理学报》2012,61(10):107804-107804
采用共沉淀法制备了不同Eu3+掺杂浓度的CaWO4荧光粉材料.通过X射线衍射和场发射扫描电镜技术对样品的结构和形貌进行了表征.测量了各样品的激发光谱、发射光谱和荧光衰减曲线, 计算了各样品的部分Judd-Oflet (J-O)参数和5D_0 (Eu3+)能级量子效率,以及荧光粉的色坐标, 讨论了样品电荷迁移带相对强度、J-O参数、量子效率与掺杂浓度的依赖关系.对Eu3+掺杂的CaWO4 发光材料的光致发光性质的研究表明,在CaWO4: Eu3+5D07F2跃迁的616~nm 红色发光能被394.5~nm和465~nm的激发光有效激发,具有近紫外(或蓝光)激发效率高和猝灭浓度大的优点, 有潜力成为高效的近紫外(或蓝光)激发白光发光二极管用红色荧光粉材料.  相似文献   

14.
Ce3+,Tb3+共掺BaYF5微晶玻璃的光学特性   总被引:2,自引:2,他引:0       下载免费PDF全文
采用高温熔融法制备了一种新型的Ce3 +/Tb3+共掺BaYF5微晶玻璃.测试了微晶玻璃的X射线衍射图(XRD)谱、激发光普和发射光谱.研究发现:660℃热处理2h后的玻璃基质中析出BaYF5纳米晶相,根据XRD结果用Scherrer公式计算得到晶粒大小约为27 nm;在近紫外光(338 nm)激发下,观察到BaYF5...  相似文献   

15.
采用高温固相法制备了系列不同浓度Eu3+离子掺杂的K2CaP2O7红色荧光粉。通过X射线衍射、扫描电子显微镜、荧光光谱和荧光寿命曲线等手段对荧光粉的物相结构、形貌以及发光性质进行了研究。结果表明所制备的荧光粉均属于单斜结构,Eu3+离子掺杂没有引起晶体结构明显变化,荧光粉形貌不规则,颗粒为微米量级且部分发生团聚。在393 nm紫外光激发下,荧光粉显示出红光发射,最强发射峰位于613 nm。Eu3+离子掺杂浓度对发光强度有显著影响,最佳掺杂摩尔分数为0.08,由此计算能量传递临界距离为1.61 nm。荧光寿命受掺杂浓度影响较小,当Eu3+掺杂摩尔分数为0.005~0.10时,荧光寿命在2.45~2.58 ms范围内。变温发射光谱显示,测试温度为150℃时,荧光粉的发光强度为室温的73%。研究表明,Eu3+离子掺杂的K2CaP2O7是性能较好的红色荧光粉。  相似文献   

16.
在化学计量的熔料里,用提拉法生长了K5Bi0.9Nd0.1(MoO4)4和K5Bi0.97Nd0.03(MoO4)4单晶。该晶体属于三方晶系,空间群为R3m,Z=1.5,晶胞常数为a=6.023?,c=20.887?(Nd0.1)。K5Bi(Mo 关键词:  相似文献   

17.
The observation of an anomalous temperature dependence of Mn2+ EPR spectra linewidth and nonaxial crystal-field parameter in K3H(SO4)2 and Rb3H(SO4)2 allows one to suggest the presence of “local mode” predicted by Yamada (Ferroelectrics 170 (1995) 23). The activation energy for this kind of excitation was found and equals 11.3 (0.5) and 7.4 (0.3) meV for Mn2+ doped K3H(SO4)2 and Rb3H(SO4)2, respectively.  相似文献   

18.
Two-inch sized KMgF3,BaLiF3 and LiCaAlF6 (LiCAF) single crystals were grown by the Czochralski method under a CF4 atmosphere. X-ray irradiation was used to carry out a comparative study of induced optical absorption phenomena and colour centre creation in the ultra-violet and visible spectral regions. The integral of the induced absorption spectra is significantly lower in LiCAF with respect to the other studied materials. It is found that the amplitude of the F-absorption band is suppressed more than a factor of 3 by Mg-doping. For Mg-doped crystals, the optimum doping concentration is about 0.2 mol% of Mg2+.  相似文献   

19.
稀土倍半氧化物单晶光纤材料凭借超高的熔点(~2400℃)、稳定的物化性能以及灵活的结构被认为是极具潜力的高温传感介质。本文采用激光加热基座(LHPG)法,成功生长了透明无开裂Dy^(3+)离子掺杂的倍半氧化物单晶光纤Lu_(2)O_(3)和Y_(2)O_(3)。依据Dy^(3+)离子的^(4)I_(15/2)和^(4)F_(9/2)能级为一对热耦合能级对(TCLs),测试得到了430~520 nm波长范围内的下转换荧光光谱。荧光强度比(FIR)结果显示,晶体在298~673 K温度范围内的荧光强度具有良好的温度相关性。其中Dy∶Lu_(2)O_(3)在该范围内的最大相对灵敏度和绝对灵敏度分别为0.97%·K^(-1)(315 K)和1.62×10^(-4) K^(-1)(673 K),展现出更为优异的温度传感性能。  相似文献   

20.
采用熔盐法制备了Sm3+掺杂的SnNb2O6粉体, 利用X射线粉末衍射、扫描电子显微镜对其物相和形貌进行了表征, 用激发、发射光谱和荧光寿命对样品的发光性能进行了研究.结果表明:所得样品为单斜晶系的SnNb2O6, 在407 nm的激发下, 有较强的橙红色发射, 最强峰位于599 nm, 属于Sm3+4G5/26H7/2跃迁.  相似文献   

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