Li2O-Ln2O3-SiO2:Eu3+,Bi3+体系的结构

采用ｓｏｌ－ｇｅｌ法合成了系列发光体Ｌｉ２Ｏ－Ｌｎ２Ｏ３－ＳｉＯ２：Ｅｕ＾３＾＋，Ｂｉ＾３＾＋，并确定了发光体的物相结构。当Ｌｎ＾３＾＋＝Ｙ＾３＾＋和Ｌｎ＾３＾＋＝Ｌａ＾３＾＋时，紫外光激发下Ｅｕ＾３＾＋的发射分别以红光和橙光为主，只存在一种Ｅｕ＾３＾＋发光中心；Ｌｎ＾３＾＋＝Ｇｄ＾３＾＋时，至少存在两种Ｅｕ＾３＾＋发光中心和两种Ｂｉ＾３＾＋发光中心（共掺杂Ｅｕ＾３＾＋，Ｂｉ＾３＾＋的吸收和发射所     

溶胶—凝胶合成（Mg,Ca）O—SiO2：Eu^3＋,Bi^3＋发光体及其发光行为

以Ｍｇ（ＮＯ３）２，Ｃａ（ＮＯ３）２，Ｅｕ（ＮＯ３）３，Ｂｉ（ＮＯ３）３和Ｓｉ（ＯＣ２Ｈ５）４为反应物，采用溶胶－凝胶法，在比较低的温度，首次合成０．７０１ｍｏｌＭｇＯ－０．１７５ｍｏｌＣａＯ－１．２５ｍｏｌＳｉＯ２：０．０６ｍｏｌＥｕ＾３＋，０．００２ｍｏｌＢｉ＾３＋（加入Ｌｉ＾＋作为电荷补偿剂）发光体，得到了最佳合成条件，研究了由溶胶向凝胶转变和凝胶向发光晶体的转变过程，探讨了发光体在不同激光     

Eu^3＋,Bi^3＋Me2Y8（SiO4）6O2中的发光特性与取代格位

在紫外光激发下，Ｅｕ＾３＋和Ｂｉ＾３＋在Ｍｅ２Ｙ８（ＳｉＯ４）６Ｏ２基质（Ｍｅ＝Ｍｇ，Ｚｎ，Ｃａ，Ｓｒ）中分别发射红光（＾５Ｄ０－＾７Ｆ２）和蓝光（＾３Ｐ１－＾１Ｓ０）．Ｅｕ＾３＋发光的红橙比随着激发波长和Ｍｅ＾２＋的不同而变化。荧光拉曼光谱表明，Ｅｕ＾３＋在四种基质中同时占据了４ｆ格位和６ｈ格位。依据Ｂｉ＾３＋发光的Ｓｔｏｋｅｓ位移推断，当Ｍｅ＝Ｃａ，Ｚｎ时，Ｂｉ＾３＋主要占据４ｆ格位，而当Ｍｅ     

Li_2O－Ln_2O_3－SiO_2：Eu~（3＋），Bi~（3＋）体系的结构

采用ｓｏｌ－ｇｅｌ法合成了系列发光体Ｌｉ２Ｏ－Ｌｎ２Ｏ３－ＳｉＯ２：Ｅｕ３＋，Ｂｉ３＋，并确定了发光体的物相结构．当Ｌｎ３＋＝Ｙ３＋和Ｌｎ３＋＝Ｌａ３＋时，紫外光激发下Ｅｕ３＋的发射分别以红光和橙光为主，只存在一种Ｅｕ３＋发光中心；Ｌｎ３＋＝Ｇｄ３＋时，至少存在两种Ｅｕ３＋发光中心和两种Ｂｉ３＋发光中心（共掺杂Ｅｕ３＋，Ｂｉ３＋），Ｂｉ３＋的吸收和发射所处的能量位置最低，４ｆ格位的Ｂｉ３＋发生了向Ｅｕ３＋的有效能量传递．     

溶胶－凝胶法合成（Mg，Ca）O－SiO_2∶Eu~（3＋），Bi~（3＋）发

以Ｍｇ（ＮＯ３）２、Ｃａ（ＮＯ３）２、Ｅｕ（ＮＯ３）３、Ｂｉ（ＮＯ３）３、ＬｉＮＯ３和Ｓｉ（ＯＣ２Ｈ５）４为反应物，采用溶胶－凝胶法，在比较低的温度下，首次合成０．７０１ｍｏＩＭｇＯ－０．１７５ｍｏｌＣａＯ－１．２５ｍｏＩＳｉＯ２∶０．０６ｍｏｌＥｕ（３＋），０．００２ｍｏＩＢｉ（３＋）（加入Ｌｉ＋作为电荷补偿剂）发光体。得到了最佳合成条件。研究了由溶胶向凝胶转变和凝胶向发光晶体的转变过程。探讨了发光体在不同激发波长激发下的发光特性以及在激活剂、敏化剂不同掺杂量下的发光行为。讨论了在（Ｍｇ（ａ）Ｏ－ＳｉＯ２基质中Ｂｉ（３＋）对Ｅｕ（３＋）的能量传递和敏化作用。     

（Sr,Ba）1—xEuxTiO3的高温高压合成及XPS研究

用高温高压法合成了Ｓｒ１－ｘＥｕｘＴｉＯ３（ｘ＝０．０，０．１，０．２，０．３，０．４，０．５）及Ｂａ０３。Ｅ０。７ＴＯ３化合物。结果表明，所有样品均为立方结构，样品中存在Ｅｕ（Ⅱ）和Ｅｕ（Ⅲ）混合价。Ｅｕ＾３＋的掺入直接影响了Ｓｒ离子与氧离子的结合。使Ｓｒ３ｐ３／２的结合能随Ｘ的增加而增加。     

Y_2O_3－Nb_2O_5－B_2O_3：Eu~（3＋）·Bi~（3＋）的燐光体的晶体结构与光谱性质

采用常规固相反应于１２００℃下制备了具有褐钇铌矿结构的Ｙ２Ｏ３·Ｎｂ２Ｏ５·Ｂ２Ｏ３（Ｙ（０．９３）Ｅｕ（０．０７））２Ｏ３·Ｎｂ２Ｏ５·Ｂ２Ｏ３和（Ｙ（０．９１）Ｅｕ（０．０７）Ｂｉ０．０２））２Ｏ３·Ｎｂ２Ｏ５·Ｂ２Ｏ３等光体，研究了它们的发光性质：结果表明，在２６８ｎｍ紫外光激发下，由于ＮｂＯ４基团于４１０ｎｍ处发生１Ｔ→１Ａ１跃迁，致使Ｙ２Ｏ５·Ｎｂ２Ｏ５·Ｂ２Ｏ３呈现更亮的紫外发射。体系中的Ｂ２Ｏ３可降低反应温度，增强ＮｂＯ４和Ｅｕ（３＋）的发光强度。（Ｙ（０．０９１）Ｅｕ（０．０７）Ｂｉ（０．０２））２Ｏ３·Ｎｂ２Ｏ５·Ｂ２Ｏ３燐光体系中所观察到的ＮｂＯ４→Ｅｕ（３＋）和Ｂｉ（３＋）→Ｅｕ（３＋）的能量传递使红光发射明显增强。     

（Sr，Ba）_（1－x）Eu_xTiO_3的高温高压合成及XPS研究

用高温高压法合成了Ｓｒ１－ｘＥｕｘＴｉＯ３（ｘ＝０．０，０．１，０．２，０．３，０．４，０．５）及Ｂａ０．３Ｅｕ０．７ＴｉＯ３化合物．结果表明，所有样品均为立方结构，样品中存在Ｅｕ（Ⅱ）和Ｅｕ（Ⅲ）的混合价．Ｅｕ３＋的掺入直接影响了Ｓｒ离子与氧离子的结合，使Ｓｒ３ｐ３／２的结合能随ｘ的增加而增加．     

硫羟乳酸作为络合滴定掩蔽剂的研究

本文系统地研究了硫羟乳酸在络合滴定中的掩蔽性能。发现在ｐＨ３．０用ＥＤＴＡ滴定了Ｔｈ＾４＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋，Ｂｉ＾３＋，Ｂｈ＾２＋和Ｃｕ＾２＋。在ｐＨ５．５滴定Ｙｂ＾３＋，Ｌａ＾３＋或Ｃｅ＾３＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋，Ｂｉ＾３＋，Ｈｇ＾２＋，Ｃｕ＾２＋和Ｃｒ＾３＋，在ｐＨ１０．０滴定Ｍｇ＾２＋时，可用它掩蔽Ｓｎ＾４＋，Ｔｌ＾３＋，Ｓｂ＾３＋     

Eu^3＋在CaYBO4中的取代和发光

用固相法制备化合物ＣａＹ１－ｘＢＯ４：ｘＥ７ｕ,研究Ｅｕ＾３＋在ＣａＹＢＯ４中的取代格位和发光特性。当Ｅｕ＾３＋掺杂浓度不大时,存在两具发光中心,认为是取代基质中有两个Ｙ格位的结果：通过对Ｅｕ－Ｏ的电荷迁移激发带位置的分析,表明Ｅｕ＾３＋所处八面体中心格位的对称性越低,Ｅｕ－Ｏ的电荷迁移带越偏向于短波;当Ｅｕ＾３＋的掺杂浓度较大（Ｘ〉０．１０）时,Ｅｕ＾３＋离子也可占据Ｃａ＾２＋格位,同时Ｅｕ＾２     

REBO3中Ce3+和Bi3+对Sm3+光致发光的影响

在紫外光(UV)激发下,系统地研究了REBO_3(RE=La,Gd,Y)中Sm~(3+),Ce~(3+)和Bi~(3+)的发射光谱、激发光谱及其发光强度与组成、结构的关系.结果表明:Ce~(3+)、Bi~(3+)均可敏化LaBO_3中Sm~(3+)的发光;而在GdBO_3和YBO_3中,只有Bi~(3+)能敏化Sm~(3+)的发光,Ce~(3+)猝灭Sm~(3+)的发光.本文还探讨了三种基质中Sm~(3+)发光浓度猝灭的机理.     

Structure and Luminescence Characteristics of Europium Activated Strontium Silicates Sr（Eu ,Bi）SiO3 and Sr（Eu ,Bi）2SiO4

Sr2SiO4 ： Eu^3 , Bi^3 and SrSiO3 ：Eu^3 , Bi^3 samples were synthesized at high temperature and high pressure. The effect of high pressure on the structure and luminescence properties of the samples were stud-ied. As a comparison, the samples were also prepared by the method of sol-gel at high temperature and atmo-spheric pressure. The SrSiO3 ： Eu^3 , Bi^3 prepared at atmosphere has a hexagonal phase structure; in the pressure range of 2. 34—4. 10 GPa, it is transformed into a pseudo-orthorhombic structure (monoclinic), and in the pressure range of 4. 10—4. 15 GPa, the structure change of Sr2SiO4 ： Eu^3 , Bi^3 has not been ob-served, it maintains the monoclinic structure of the samples synthesized at an atmospheric pressure. High pressure makes the luminescence properties of the samples changed obviously. The intensity and the relative quantum luminescent efficiency decrease, the half-width increases obviously and the red shift occurs. The changes of the luminescence properties result from the pressure-induced changes of the crystal structures.     

Ce3+,Tb3+,Eu3+共掺杂Sr2MgSi2O7体系的白色发光和能量传递机理

通过正交试验,采用高温固相法制备了Sr2-x-y-zMgSi2O7∶xCe3+,yTb3+,zEu3+系列样品.使用X射线衍射仪和荧光光谱仪表征了样品的物相和发光性质,并讨论了Ce3+-Tb3+-Eu3+共掺杂Sr2MgSi2O7体系中的能量传递过程.实验结果表明,在327 nm波长激发下,所合成荧光粉的发射峰主要位于387 nm(蓝紫)、542nm(绿)和611 nm(红)处;分别以387,542和611 nm为监控波长,所得激发光谱显示荧光粉在327 nm处有最好的激发.在327 nm光激发下,系列样品发光进入白光区.最优化的荧光粉为Sr1.91MgSi2O7∶0.01Ce3+,0.05Tb3+,0.03Eu3+,其色坐标为(0.337,0.313),是一种潜在的发光二极管(LED)用白色荧光粉.     

Vacuum Ultraviolet Excited Photoluminescence Properties of Y202S:Eu3+,Bi3+ Phosphor

As an Hg-free lamp using phosphor,the Bi3+ and Eu3+ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum uitraviolet(VUV) excitation were investigated.The VUV photolumineseent intensity of Y2O2S:Eu3+ was weak,however,considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S:Eu3+,Bi3+ systems.Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S:Eu3+,Bi3+ at 147 nm is mainly because the Bi3+ acts as a medium and effectively performs the energy transfer process: Y3+-O2→Bi3+→Eu3+,while the intense emission band at 172 nm is attributed to the absorption of the characteristic 1So-1P1 transition of Bi3+ and the direct energy transfer from Bi3+ to Eu3+.The Y2O2S:Eu3+,Bi3+ shows excellent VUV optical properties compared with the commercial (Y,Gd)BO3:Eu3+.Thus,the Y2O2S:Eu3+,Bi3+ can be a potential red VUV-excited candidate applied in Hg-free lamps for backlight of liquid crystal display.     

镧系(Nd3+、Ho3+、Er3+)与1-苯基-3-甲基-4-三氟乙酰基吡唑酮-5和二安替吡啉甲烷三元配合物的研究

用分光光度法对镧系离子(Nd~(3+),Ho~(3+),Er~(3+))与1-苯基-3-甲基-4-三氟乙酰基吡唑酮-5(PMTFP)和二安替吡啉甲烷(DAM)水-乙醇溶液体系的研究以及对制备钕的相应配合物的元素分析证实:形成的三元配合物的的组成比为Ln~(3+):PMTFP:DAM=1:3:1。计算了相应配合物超灵敏跃迁的光吸收振子强度,并图示了它们之间的线性关系。研究了固态钕的三元配合物的红外吸收光谱和热稳定性。 镧系离子(Ln~(3+))同DAM和1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(PMBP)等β-二酮以及Ln~(3+)与PMTFP和三辛基磷氧化物(TOPO)的三元配合物的研究已有报导。本文报导了Ln~(3+)(Nd~(3+)、Ho~(3+)、Er~(3+))-PMTFP-DAM体系中的超灵敏跃迁现象与配位作用,以及Nd(Ⅲ)-PMTFP-DAM配合物的合成、组成和性质。     

Enhanced red light emission from LaBSiO5:Eu3+,R3+ (R=Bi or Sm) phosphors

Polycrystalline LaBSiO5:Eu3+,R3+ (R=Bi or Sm) phosphors have been synthesized by a facile sol-gel method. The phosphors have been characterized by thermogravimetric analysis/different scanning calorimeter, scanning electron microscopy, X-ray diffractometer and fluorescence measurements. It was found that the emission intensity of LaBSiO5:Eu phosphors increases clearly and reaches a maximum at 30 mol% with increasing of Eu3+ concentration. The incorporation of Bi3+ ions and/or Sm3+ ions have greatly enhanced the emission intensity of Eu3+ upon excitation with 391 nm light. The possible sensitization mechanisms of Sm3+ and/or Bi3+ on Eu3+ emission intensity have been investigated and discussed. The high brightness and short luminescence decay times make it promising red-emitting candidates for white light-emitting diodes.     

Ca3La3(BO3)5中Eu3+的光致发光

本文详细地研究了紫外光激发下,Ca_3La_3(BO_3)_5中Eu~(3+)的发光光谱和激发光谱与组成、结构的关系.发现Eu~(3+)在此基质中可能不止一个发光中心;Eu~(3+)自身浓度猝灭的机理为电四极-四极相互作用.     

Vacuum Ultraviolet Excited Photoluminescence Properties of Y2O2S：Eu^3＋,Bi^3＋ Phosphor

As an Hg-free lamp using phosphor, the Bi3+ and Eu3+ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet(VUV) excitation were investigated. The VUV photoluminescent intensity of Y2O2S:Eu3+ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S:Eu3+,Bi3+ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S:Eu3+,Bi3+ at 147 nm is mainly because the Bi3+ acts as a med...     

Eu3+在碱土金属卤磷酸盐中的格位对称性及电荷迁移态

在254nm紫外光激发下研究了Eu~(3+)在Sr_3Ca_2(PO_4)_3Cl基质中的发光光谱.以Eu~(3+)为结构探针测定了Eu~(3+)所处晶格的点对称性.研究了M_5(PO_4)_3X(M=Ca,Sr,Ba;X=F,Cl,Br)基质组成改变对Eu~(3+)电荷迁移态的影响,以及温度对Ca_5(PO_4)_3Cl:Eu~(3+)发光强度的影响.