邻氨基苯甲酸2,2′-联吡啶铕镧混合稀土配合物的红外及荧光研究

用邻氨基苯甲酸和２,２′－联吡啶与氯化铕和氯化镧在溶液中反应,合成了混合混合稀土配合物,测定了配合物的红外光谱及荧光光谱,结果表明,稀土离子均与配体形成配合物,在３４３ｎｍ紫外光激发下,在一定范围内,用不发光的Ｌａ＾３＋离子取代邻氨基苯甲酸－２,２′联吡啶铕配合物中的Ｅｕ＾３＋离子,可以提高Ｅｕ＾３＋离子的特征发光强度,而对发射峰位影响不大,本文对发光机理进行了初探。     

MAl2O4：Eu^2＋,RE^3＋,长余辉发光性质的研究

研究鳞石英结构碱土铝酸盐ＭＡｌ２Ｏ４：Ｅｕ＾２＋,ＲＥ＾＋（Ｍ＝Ｍｇ,Ｃａ,Ｓｒ,Ｂａ：ＲＥ＝Ｙ,Ｌａ,Ｃｅ,Ｐｒ,Ｎｄ,Ｓｍ,Ｇｄ,Ｔｂ,Ｄｙ,Ｈｏ,Ｅｒ,Ｔｂ,Ｄｙ,Ｈｏ,Ｅｒ,Ｔｍ,Ｙｍ,Ｙｂ,Ｌｕ）的荧光及长余辉发光性质。其发光由Ｅｕ＾２＋的４ｆ－５ｄ跃迁产生。ＲＥ＾３＋作为辅助激离子,提供合适的陷阱能级。即使用ＲＥ＾３＋的特性波长激发,在ＭＡｌ２Ｏ４：Ｅｕ＾３＋的发光中也观察不到ＲＥ＾３     

苯甲酸稀土(Eu,La)配合物的红外和荧光光谱研究

用氯化稀土与苯甲酸铵在水溶液中反应,合成了苯甲酸稀土（Ｅｕ,Ｌａ）三元固体系列配合物,其化学组成式为（Ｅｕ１－ｘＬａｘ）Ｌ３（其中Ｌ为Ｃ６Ｈ５ＣＯＯ－,ｘ＝０．０～１．０）。研究了它们的红外光谱和荧光光谱。由红外光谱数据表明,配合物中羧基的对称和反对称伸缩振动吸收峰发生了分裂,而且羧基伸缩振动随着Ｌａ３＋离子含量的增加发生了规律性的变化。荧光光谱实验结果表明,用不发光的Ｌａ３＋离子取代苯甲酸铕中部分Ｅｕ３＋离子可以提高Ｅｕ３＋离子的特征荧光发射强度。     

A3Ln（Ⅲ）1—xTb（Ⅲ）x（A=邻氨基苯甲酸;Ln=La,Gd,Y;x=0—0.1）稀土配？…

采用共沉淀法合成了掺杂Ｌａ、Ｇｄ、Ｙ的Ｔｂ－邻氨基苯甲酸配合物,研究其荧光性能,结果显示,掺杂Ｌａ、Ｇｄ、Ｙ后,对Ｔｂ配合物的发光有增敏作用,讨论了不同的掺杂离子（Ｌａ、Ｇｄ、Ｙ）及掺杂量对其荧光性能的影响。发现,当掺杂离子取代大部分Ｔｂ＾３＋时,其发光增强仍十分显著。     

稀土（Eu^3＋,Tb^3＋）含氮杂环配合物的合成,表征及其荧光性质

在无水乙醇溶液中分别合成了Ｅｕ＾２＋离子、Ｔｂ＾３＋离子与２，２‘－联吡啶、１，１０－邻菲罗啉押种配合物，研究了配合物的荧光性质，由于Ｐｈｅｎ含有较大范围的共轭π键和较好的刚性平面，含Ｐｈｅｎ配合物的荧光强度均要比配合物的强；配合物的高分辨荧光光谱表明，Ｅｕ＾３＋离子在Ｅｕ（Ｄｉｐｙ）２Ｃｌ３’２Ｈ２Ｏ和Ｅｕ（Ｐｈｅｎ）２Ｃｌ３．２Ｈ２Ｏ配合物中处于Ｃ１或Ｃ２或Ｃ５的对称性位置。     

铕与对甲基苯甲酸及2,2‘—联吡啶三元配合物的谱学研究

元素分析表明稀土铕（Ｅｕ＾３＋）与对甲基苯甲酸（Ｐ－ＭＢＡ）及２，２’－联吡啶（ｄｉｐｙ）形成的三元配合物组成为Ｅｕ２（Ｐ－ＭＢＡ）６（ｄｉｐｙ）２对甲基苯甲酸，２，２’－联吡啶均以双齿配位，中心铕离子的配位数为８，两个铕离子通过四个对甲基苯甲酸基桥联，形成双核配合物，对该配合物的结构作了核磁共振氢谱，碳谱及红外光谱的研究。     

（Gd,Y）P5O14：Ce,Tb中Gd的中介能量传递和传递几率计算

研究了稀土五磷酸盐ＧｄｘＹ１－ｘ）Ｐ５Ｏ１４：Ｃｅ０．０１，Ｔｂ０．０２体系中以Ｇｄ＾３＋子晶格为中介的Ｃｅ＾３＋→Ｇｄ＾３＋→Ｔｂ＾３＋的能量传递现象。当ｘ＞０．７，在室温下激发Ｃｅ＾３＋离子可以产生有效的Ｔｂ＾３＋的发光。对ｘ＝１和０时，激发Ｃｅ＾３＋产生Ｔｂ＾３＋的发光，前者的强度约为后者的１０倍。     

均苯四甲酸-三苯基氧化膦-铽-钇配合物的高效发光

合成了ＰＭＡ－Ｔｂ＾３＋,ＰＭ－ＡＴＰＰＯ（Ｐｈｅｎ）－Ｔｂ＾３＋及其掺杂Ｙ＾３＋,Ｇｄ６３＋的系列配合物,常温下研究了它们的固体粉末荧光光谱,发现在二元配合物中掺杂Ｙ＾３＋比掺杂Ｇｄ＾３＋发光强,在三元配合物中以三苯基氧化膦作第二配体比以邻菲罗林作第二配体的配合物发光强,得到了鲜艳绿色的高效荧光材料ＰＭＡ－ＴＰＰＯ－Ｔｂ＾３＋,Ｙ＾３＋。     

腩（Ⅲ）多核配合物的形成及其荧光增强效应

利用荧光增强盗中成了铕（Ⅲ）异多核固体物，通过元素分析等离子体发射光谱、红外光谱、荧光光谱等测试手段研究事物的组成、结构和发光性质。结果表明增强离子Ｇｄ＾３＋、Ｌａ＾３＋和Ｙ＾３＋离子的加入能显著的提高配合物中ＥＵ＾３＋中心的发光强 种荧光效应能减少较为贵的铕在配合物中的用量，从而降侈产品的成本。     

多体系多波长计算光度法同时测定镧铈谱钕钐铕钆

本文以ＤＢＣ－偶氮氯膦为显色剂,并且在显色体系中加入不同量的ＥＤＴＡ－Ｎａ２Ｐ２Ｏ７作为竞争配位剂,使得七组分轻稀土组分间吸收光谱灵敏度的差别逐渐加大,从而增加了轻稀土混合物体系组分间吸收光谱的线性独立性。利用数值稳定性较强的约束优化算法－可变容差法处理光谱数据,对不同浓度比例的七组分轻稀土混合物体系（Ｌａ＾３＋,Ｃｅ＾３＋,Ｐｒ＾３＋,Ｎｄ＾３＋,Ｓｍ＾３＋,Ｅｕ＾３＋,Ｇｄ＾３＋）的测定,取得     

Cooperative energy transfer and frequency upconversion in Yb3+-Tb 3+ and Nd 3+-Yb 3+-Tb 3+ codoped GdAl3(BO3)4 phosphors

Polycrystalline GdAl₃(BO₃)₄ phosphors codoped with Yb³⁺/Tb³⁺ and/or Nd³⁺/Yb³⁺/Tb³⁺ have been synthesized by combustion method. Upon excitation with a 980 nm laser diode, an intense green upconversion luminescence has been observed in GdAl₃(BO₃)₄:Yb,Tb phosphor. The quadratic dependence of the luminescence on the pump-laser power indicating a cooperative energy transfer process. Meanwhile, it is noticed that upon excitation with 808 nm laser diode, intense luminescence has clearly been detected in GdAl₃(BO₃)₄:Nd,Yb,Tb phosphor. The luminescence intensity exhibits also a quadratic dependence on incident pump-laser power. However, no green-emission has been observed in GdAl₃(BO₃)₄ phosphors codoped with Yb³⁺/Tb³⁺ or Nd³⁺/Tb³⁺ respectively upon excited at 808 nm laser diode. A proposed upconversion mechanism involving energy transfer from Nd³⁺ to Yb³⁺, and then a cooperative energy transfer process from two excited Yb³⁺ to Tb³⁺ has been presented.     

Optical spectroscopy of Cr3+ and Cr3+-Tm3+ in alkaline silicate glasses

Conclusions Alkaline silicate glasses seem to be good candidates as host materials for codoping with Cr³⁺ and Tm³⁺. Cr³⁺ ions occupy mainly low-field sites in them, and their broadband emission overlaps Tm³⁺ excitation. As a consequence very high efficiency for the energy transfer Cr³⁺→Tm³⁺ is achieved with moderate concentrations of these ions. Moreover, the average lifetime of the Cr³⁺ ions in codoped glasses is long enough to allow significant energy storage by flashlamp pumping. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 5, pp. 115–120, September–October, 1995.     

Stark splitting and energy transfer between Dy3+-Ho3+ and between Tb3+-Er3+ in calcium-lithium borate glass

Fluorescence spectrum of Dy³⁺, Dy³⁺-Ho³⁺, Tb³⁺ and Tb³⁺-Er³⁺ doped in calibo glass have been studied using Ar⁺ and excimer lasers. Non-radiative energy transfer from trivalent dysprosium and terbium (donors) to holmium and erbium (acceptors) respectively has been observed on the basis of decrease in the life time of the levels and reduction in fluorescence intensity of Dy³⁺ and Tb³⁺ on increasing Ho and Er concentrations. The interaction mechanism of donor and acceptor ions is found to be dipole-dipole in both cases. Various parameters such as donor-acceptor distances, non-radiative energy transfer efficiency (η) and energy transfer probability (P _da) have been computed. Stark splitting have also been marked in several intense transition of the two.     

Er~(3+)及Er~(3+)/Yb~(3+)掺杂纳米晶CaWO_4的发光性质

利用共沉淀法制备了Er3+掺杂及Er3+/Yb3+共掺杂纳米晶CaWO4发光粉体,室温下观察到Er3+的下转换和上转换特征发射。研究了不同煅烧温度、不同掺杂浓度对Er3+离子特征发射的影响。结果表明:随着煅烧温度的升高,发射强度增强;掺杂浓度的改变,导致了Er3+的浓度猝灭现象,其适宜的掺杂原子数分数为0.6%。同时观测到O-W的电荷迁移态与稀土离子之间的能量传递现象,并给出了能量传递的模型。对Er3+的上转换研究观察到:在976nm激光激发下Yb3+对Er3+的上转换发射起到了很好的敏化作用,两个Yb3+同时将能量以共振方式传递给一个Er3+离子,Er3+、Yb3+共掺杂样品的绿光上转换过程展示了双光子过程。     

Luminescence properties of Nd3+, Sm3+ and Eu3+ intercalated CdPS3

Nd³⁺, Sm³⁺ and Eu³⁺ have been intercalated by cation exchange into CdPS₃. The photoluminescence and IR spectra show the creation of cadmium cation vacancies. Crystal field analysis indicates that the rare earths have entered the intralamellar vacancies and formed a complex defect center with C₂ or lower symmetry.     

Spectroscopy of Ce3+-doped and Ce3+-concentrated scintillators

Institute of Physics, Czech Academy of Sciences, Cukrovarnicka 10, 16200 Prague 6, Czech Republic. Published in Zhurnal Prikladnoi Spektroskopii, Vo. 62, No. 5, pp. 71–77, September–October, 1995.     

Preparation and fluorescence properties of Yb3+ and Er3+ co-doped GdAlO3 phosphors

Yb³⁺ and Er³⁺ co-doped GdAlO₃ phosphors are prepared by the sol–gel method. The effect of doping concentration on the structure and fluorescence properties is investigated by X-ray diffraction (XRD) and photoluminescence, respectively. XRD pattern indicates that the sample structure belongs to orthorhombic. The photoluminescence results show that both green and red fluorescence emission and upconversion emission intensities decrease with an increase in Yb³⁺ concentration due to the cross-relaxation process between Yb³⁺ and Er³⁺ ions. Based on the emission spectra, the mechanism of the upconversion emission is discussed, and we concluded that the upconversion emission is a two-photon process.     

在NaGdF4：Tm3+, Dy3+中Gd3+间的能量迁移及Gd3+-Dy3+能量传递量子效率

基于量子剪裁基本原理,通过光谱技术研究NaGdF₄:Tm³⁺,Dy³⁺在一个真空紫外光子激发下获得两个蓝色光子的可能性。在这种化合物中,量子剪裁通过下转换,即通过应用不同镧系离子间的能量传递进行。通过对Tm 4f¹²-4f¹¹5d激发,部分能量从Tm³⁺离子5d态直接传递给Gd³⁺,然后在Gd³⁺-Tm³⁺之间发生交叉弛豫,剩余能量从Gd³⁺传递给Dy³⁺,产生两个可见光子发射,一个来自Tm³⁺的¹G₄-³H₆跃迁,另一个来自Dy³⁺的⁴F_9/2-⁶H_15/2跃迁。主要研究获得以NaGdF₄:Tm³⁺,Dy³⁺为基础的新型具有更高效率,更高稳定性和更强真空紫外(VUV)吸收量子剪裁发光粉的可能性。各种光谱技术,如光致发光、激发和衰减等被用来表征不同Dy³⁺浓度掺杂NaGdF₄中Gd³⁺晶格间能量迁移引起的施主Gd³⁺和受主Dy³⁺之间的能量传递。结果表明Gd³⁺离子之间存在能量迁移,随之交换相互作用引起施主与受主(Gd³⁺-Dy³⁺)之间的能量传递。通过Bursh-tein等人关于激发态的弛豫理论,施主-受主能量传递参数k_DS可以从Gd³⁺的⁶P_7/2发射的衰减计算出。Gd³⁺-Dy³⁺能量传递量子效率也可以得到。NaGdF₄:Tm³⁺和NaGdF₄:Tm³⁺,Dy³⁺是由水热法制备的,NaGdF₄:Dy³⁺是由文献[4]方法制备的。发射光谱和激发光谱通过自制的VUV光谱仪和F-4500测量。衰减曲线由OPO激光器激发获得Gd³⁺-Dy³⁺之间能量传递量子效率在受主浓度大约在N_A=0.6%时达到最佳值,并且明显地观测到浓度猝灭效应。