KZnF3中Ce^3＋→Eu^2＋的能量传递

研究了ＫＺｎＦ３中Ｃｅ＾２＋和Ｅｕ＾２＋的光谱特性,在共掺Ｃｅ＾３＋和Ｅｕ＾２＋的体系中,观察到了Ｃｅ＾３＋对Ｅｕ＾２＋的能量传递过程,计算了能量传递的量子效率,探讨了能量传递机理,研究发现,Ｃｅ＾３＋的存在有利于Ｅｕ＾２＋的ｆ－ｆ跃迁线状发射。     

单基双掺稀土三基色荧光体系的发光特性

利用Ｅｕ＾３＋和Ｔｆｂ＾３＋对一对三价稀土离子之间电子组态具有共轭性的特征,双掺到同一基质中,由于电子转移,部分Ｅｕ＾３＋转换成Ｅｕ＾２＋,使发红光的Ｅｕ＾３＋、发绿光的Ｔｂ＾３＋和发蓝光的Ｅｕ＾２＋共存于同一体系。在空气气氛中合成了单基双掺稀土三基色荧光粉ＣａＢＰＯ５：Ｅｕ,Ｔｂ,研究了２５４和３６５ｎｍ激发下荧光体的发射特性。在双掺体系中引入Ｃｅ＾３＋,由于Ｃｅ＾３＋的敏化作用增强了Ｅｕ＾２＿     

GdxY1—XP5O14：Ce,Tb的发光和能量传递：Ⅰ.制备,结构和光谱性质

研究了稀土五磷酸盐Ｇｄｘ１－ＸＰ５Ｏ１４：Ｃｅ，Ｔｂ体系的制备，结构和光谱性质。当ｘ＞０．７时，该材料属单斜晶系Ｉ，Ｐ２１／ｃ结构，当≤０．７时，属单斜晶系Ⅱ，Ｃ２／ｃ结构。研究了ＧｄＰ５Ｏ１４：Ｃｅ，Ｔｂ６ ＹＰ５Ｏ１４：Ｃｅ，Ｔｂ的荧光光谱，确定了通过基质Ｇｄ离子中介的Ｃｅ＾３＋→Ｇｄ＾３＋→Ｔｂ＾３＋能量传递的现象。     

Tb^3＋,Ca^2＋与天花粉蛋白的结合效应

利用Ｔｂ＾３＋作为荧光探针研究天花粉蛋白（ＴＣＳ）的结构，Ｔｂ＾３＋可转换天花粉蛋白中的Ｃａ＾２＋，发生从ＴＣＳ分子中的Ｔｒｐ残基到Ｔｂ＾３的能量传递，使Ｔｒｐ的荧光发射强度减弱，光谱技术，Ｔｂ＾３＋与ＴＣＳ亲和力小于Ｃａ＾２＋与ＴＣＳ的亲和力；Ｔｂ＾３＋与ＴＣＳ亲和力小于Ｃａ＾２＋与ＴＣＳ的亲和力；Ｔｂ＾３＋与其结合后基本不改变ＴＣＳ的构象，但Ｔｒｐ和Ｔｙｒ残基处的微环境发生变化；Ｃａ＾２＋对Ｔ     

SrF2晶体中Ho3+-Ho3+离子对的上转换发光研究

研究了在连续调谐以染料激光激发下,掺杂Ｈｏ＾３＋离子的ＳｒＦ２单晶中Ｈｏｌ＾３＋－Ｈｏ＾３＋对的上转换发光特性。Ｈｏ＾３＋－Ｈｏ＾３＋离子对的上转换发光主要分布于;强＾５Ｆ３→＾５Ｉ８跃迁４８０ｎｍ蓝色发射,较强＾５Ｓ２,＾５Ｆ４→＾５Ｉ８跃迁的５４０ｎｍ绿色发射。     

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     

稀土离子与牛血Cu（Zn）—SOD的作用

采用ＥＳＲ、ＣＤ谱和荧光光谱研究了ｐＨ＝６．３时六次甲基四胺－ＨＣｌ缓冲溶液中ＬａＣｌ３和ＴｂＣｌ３与Ｃｕ（Ｚｎ）－ＳＯＤ的配位作用和结构。Ｃｕ（Ｚｎ）－ＳＯＤ可增强Ｔｂ＾３＋的荧光发射，Ｔｂ＾３＋与Ｃｕ（Ｚｎ）－ＳＯＤ有多个配位位置，其中有２个强结合位点，Ｌａ＾３＋可Ｔｂ＾３＋可竞争Ｃｕ（Ｚｎ）…ＳＯＤ上相同结合位点，７７Ｋ下Ｌａ＾３＋与Ｔｂ＾３＋使Ｃｕ（Ｚｎ）－ＳＯＤ的Ｃｕ＾２＋活性中心的配位     

荧光光度法同时测定稀土氧化物中铈钆铽

在０．６ｍｏｌ．Ｌ＾－１的 到介质中,分别用２５２、２７３、２２０ｎｍ作为Ｃｅ＾３＋、Ｇｄ＾３＋、Ｔｂ＾３＋的激发波和燕生相应最佳发波长为３５０、３１０和５４４ｎｍ。用盐酸体系测定混合样比用硫酸体系测定时,Ｇｄ＾３＋的检出限提高一倍,Ｇｄ＾３＋抗Ｃｅ＾３＋的干扰能力提高１０倍。同时测定三种离子的回收率在９５．３％～１０８．１％之间。     

Gd_xY_（1－x）P_5O_（14）：Ce，Tb的发光和能量传递Ⅱ．Ce→

研究了Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ＿（０．０１），Ｔｂ＿（０．０２）体系中Ｇｄ的子晶格在Ｃｅ→Ｇｄ→Ｔｂ能量传递中的中介作用规律及ＧｄＰ＿５Ｏ＿（１４），ＧｄＰ＿５Ｏ＿（１４）：Ｃｅ，ＧｄＰ＿５Ｏ＿（１４）：Ｔｂ和Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ，Ｔｂ的荧光光谱、激发光谱。结果表明，当ｘ＞０．７时，结构从单斜Ⅱ（Ｃ２／ｃ）的层状结构变为单斜Ｉ（Ｐ２＿１／ｃ）的带状结构，Ｃｅ￣（３＋）的发射光谱和Ｇｄ￣（３＋）的吸收光谱交迭增加等是Ｃｅ￣（３＋）→Ｇｄ￣（３＋）→Ｔｂ￣（３＋）能量传递几率增加的主要原因。     

Gd_xY_（1－x）P_5O_（14）：Ce，Tb的发光和能量传递I．制备、

研究了稀土五磷酸盐ＧｄｘＹ１－ｘＰ５Ｏ１４：Ｃｅ，Ｔｂ体系的制备，结构和光谱性质，当ｘ＞０．７时，该材料属单斜晶系结构当ｘ≤０．７时，属单斜晶系结构。研究了ＧｄＰ５Ｏ１４：Ｃｅ，Ｔｈ和ＧｄｘＹ１－ｘＰ５Ｏ１４：Ｃｅ，Ｔｂ的荧光光谱，确定了通过基质Ｇｄ离子中介的Ｃｅ３＋→Ｇｄ３＋→Ｔｂ３＋能量传递的现象。     

在硅磷酸镧中Ce^3＋离子对Tb^3＋离子的敏化

实验表明在La2O3·0.01SiO2·0.95P2O5基质中Ce^3 对Tb^3 有强的敏化作用。254nm紫外光激发下温度对Tb^3 激活的Ce^3 、Tb^3 共激活试样的发射强度的Ce^3 、Tb^3 共激活的试样Tb^3 的^5D4→^7F6:5:4跃迁的发射强度随湿度的变化。计算了Ce^3 到Tb^3 的能量传递效率。初步探讨了Ce对Tb的能量传递机理。     

Ce/Tb/Sm共掺杂CaO-B2O3-SiO2发光玻璃的白光发射及其发光颜色调控

用高温熔融法制备了Ce/Tb/Sm三元共掺杂的CaO-B2O3-SiO2发光玻璃材料,并使用荧光分光光度计和CIE色度坐标对其光谱学和发光特性进行了研究.结果表明:在374nm激发下,在Ce/Tb/Sm三元共掺杂发光玻璃的发射光谱中同时观测到了蓝光、绿光和红橙光的发射带,这些发射带的混合实现了白光的全色发射显示.此外,Ce/Tb/Sm三元共掺杂发光玻璃的发光颜色随着Tb4O7含量的减小从绿光逐渐过渡到白光,显示出发光颜色的可调节性,极大地扩展了其在白光发光二极管中的应用.     

磷灰石结构荧光粉Ba10(PO4)6F2:Ce3+,Tb3+的合成、发光和能量传递

采用高温固相法合成了系列Ce~(3+)和Ce~(3+)/Tb~(3+)激活的具有磷灰石结构荧光粉Ba_(10)(PO_4)_6F_2。用X射线衍射(XRD)、扫描电镜(SEM)、激发和发射(PLE和PL)光谱对样品进行了表征分析。研究结果表明:所合成的荧光粉Ba_(10)(PO_4)_6F_2∶Ce~(3+),Tb~(3+)具有氟磷灰石结构,样品微观呈现不规则形貌。荧光粉Ba10-x(PO4)6F2∶x Ce~(3+)的相对发射强度随着x增加而增强,当x=0.09时,荧光强度达到最大。荧光粉Ba_(10)(PO_4)_6F_2∶Ce~(3+),Tb~(3+)的激发光谱为240～330 nm的宽带,发射光谱呈现出Ce~(3+)的5d→4f跃迁紫外光(335和358 nm)发射和Tb~(3+)的4f→4f跃迁绿光(542 nm)发射。光谱特性表明,发光过程中存在Ce~(3+)→Tb~(3+)能量传递,能量传递效率可以达到60%。计算Ce~(3+)和Tb~(3+)的临界距离为0.79 nm,能量传递机理是偶极-偶极交互作用。此外,详细论述了Ce~(3+)和Tb~(3+)之间的能量传递和发光的过程。通过调节Tb~(3+)的掺杂浓度,对荧光粉发光色坐标与Tb~(3+)的掺杂浓度之间的关系也进行了研究,随着Tb~(3+)的掺杂量从0增加0.52,荧光粉Ba_(10)(PO_4)_6F_2∶Ce~(3+),Tb~(3+)的发射光谱色坐标可以从(0.149 4,0.045 1)蓝色区变化到(0.280 1,0.585 3)绿色区。     

GdAlO_3∶Tb,RE中Tb,RE的能量传递研究

采用柠檬酸盐硝酸盐燃烧法制备了GdAlO3∶Tb,RE荧光粉体.在紫外激发下(254nm),GdAlO3∶Tb发射绿色荧光(5D4→7F5,544nm),Dy共掺杂对绿色发光有增强作用,Ce共掺杂对GdAlO3∶Tb绿色发光有降低作用.激发谱和能谱研究表明:Dy能级嵌入Tb主发射能级5D4(绿色发光能级)、5D3(蓝色发光能级)能级之间,Ce能级嵌入Tb主发射能级5D4、5D3能级上方.这种能级嵌入方式,使得稀土离子之间存在声子支持的共振能量传递,但Tb→Dy→Tb能量传递使Tb绿色发射(5D4→7FJ(J=3,4,5,6))增强,蓝色发射(5D3→7FJ(J=3,4,5,6))减弱;而Ce→Tb能量传递使Tb蓝色发射增强,绿色发射减弱.     

Laser spectroscopic studies of Tb3+-doped oxyfluoroborate glass

Tb3+-doped oxyfluoroborate glasses have been prepared for different concentrations of Tb. The absorption, fluorescence and photoacoustic spectra of these have been recorded and studied. It is marked that the fluorescence intensity of different fluorescence transitions decreases with the increase of Tb ion concentration in the glass. This quenching at higher concentration is due to the energy transfer among the excited and nearest neighbor unexcited Tb ions in the glass. The lifetime measurement confirms it, as the lifetime of a particular state was found to decrease with the increase of Tb ion concentration in the glass. The mechanism of the energy transfer process was determined to involve quadrupole quadrupole interaction. We have also studied the energy transfer from Tb3+-->Pr3+ when both the rare earths are doped together in the glass. A decrease in the lifetime of the 5D4 level of Tb3+ with the increase of Pr3+ concentration confirms this.     

新型GdAlO_3:RE荧光粉多元掺杂及发光机制研究

采用柠檬酸盐硝酸盐燃烧法制备GdAlO3:RE荧光粉体.在紫外光激发下(254nm)发现Pr共掺杂对GdAlO3:Eu红色荧光粉体发光有降低作用;Ce共掺杂对GdAlO3:Tb绿色荧光粉体发光有降低作用.激发谱研究表明,共掺杂时分别存在Eu→Pr、Tb→Ce的声子支持的共振能量传递,造成GdAlO3:Eu、GdAlO3:Tb荧光粉体发光强度降低.     

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.     

Electronic transition and energy transfer processes in LaPO4-Ce3+/Tb3+ nanowires

Ce3+ and Tb3+ coactivated LaPO4 nanowires and micrometer rods were synthesized by hydrothermal methods. Their fluorescent spectra and dynamics were systematically studied and compared. The results indicated that the extinction coefficients of Ce3+ and Tb3+ in nanowires were higher than those in micrometer rods. The electronic transition rates of Ce3+ and Tb3+ in nanowires had little variation in contrast to those in micrometer rods, and the energy transfer rate and efficiency of Ce3+ --> Tb3+ in nanowires were reduced greatly. It is important to observe that the brightness for the 5D4-7F5 green emissions of Tb3+ via energy transfer of Ce3+ --> Tb3+ in nanowires increased several times that in micrometer rods. This was attributed to the decreased energy loss in the excited states, being higher than 5D4 due to the hindrance of the boundary.     

Strong visible up-conversion emission in Tb3+, Tm3+ and Tb3+-Tm3+ co-doped tellurite glasses sensitized by Yb3+

Up-conversion luminescence characteristics under 975 nm excitation have been investigated with Tb3+/Tm3+/Yb3+ triply doped tellurite glasses. Here, green (547 nm: (5)D(4)-->(7)F(4)) and red (660 nm: (5)D(4)-->(7)F(2)) up-conversion (UC) luminescence originating from Tb3+ is observed strongly, because of the quadratic dependences of emission intensities on the excitation power. Especially, the UC luminescence was intensified violently with the energy transfer from the Tm3+ ions involves in the Tb3+ excitation. To the Tb3+/Tm3+/Yb3+ triply doped glass system, a novel up-conversion mechanism is proposed as follows: the energy of (3)G(4) level (Tm3+) was transferred to (5)D(4) (Tb(3+)) and the 477-nm UC luminescence of Tm3+ was nearly quenched.     

Luminescence and energy transfer in lu(3)al(5)o(12) scintillators co-doped with ce(3+) and tb(3+)

Lu(3)Al(5)O(12) (LuAG) doped with Ce(3+) is a promising scintillator material with a high density and a fast response time. The light output under X-ray or γ-ray excitation is, however, well below the theoretical limit. In this paper the influence of codoping with Tb(3+) is investigated with the aim to increase the light output. High resolution spectra of singly doped LuAG (with Ce(3+) or Tb(3+)) are reported and provide insight into the energy level structure of the two ions in LuAG. For Ce(3+) zero-phonon lines and vibronic structure are observed for the two lowest energy 5d bands and the Stokes' shift (2 350 cm(-1)) and Huang-Rhys coupling parameter (S = 9) have been determined. Tb(3+) 4f-5d transitions to the high spin (HS) and low spin (LS) states are observed (including a zero-phonon line and vibrational structure for the high spin state). The HS-LS splitting of 5400 cm(-1) is smaller than usually observed and is explained by a reduction of the 5d-4f exchange coupling parameter J by covalency. Upon replacing the smaller Lu(3+) ion with the larger Tb(3+) ion, the crystal field splitting for the lowest 5d states increases, causing the lowest 5d state to shift below the (5)D(4) state of Tb(3+) and allowing for efficient energy transfer from Tb(3+) to Ce(3+) down to the lowest temperatures. Luminescence decay measurements confirm efficient energy transfer from Tb(3+) to Ce(3+) and provide a qualitative understanding of the energy transfer process. Co-doping with Tb(3+) does not result in the desired increase in light output, and an explanation based on electron trapping in defects is discussed.