CaTiO3：Pr^3＋的合成及发光性质

报道了稀土离子Ｐｒ＾３＋激活的ＣａＴｉＯ３发光材料的合成方法ＣａＴｉＯ３：Ｐｒ＾３＋位于６１３ｎｍ发射与Ｐｒ＾３＋离子＾１Ｄ２－＾３Ｈ４和光谱发射相一致，讨论了不同合成条件对ＣａＴｉＯ３：Ｐｒ＾３＋发光性持的影响。Ｃ     

REBO3基质中Sm^3＋的阴极射线发光特性

ＲＥＢＯ＿３基质中Ｓｍ￣（３＋）的阴极射线发光特性郭凤瑜彭夷安（北京大学１００８７１）（湖南医学专科学校）ＲＥＢＯ＿３（ＲＢ＝Ｌａ、Ｇｄ、Ｙ）是一类优良的发光材料的基质。对于ＲＥＢＯ＿３中稀土离子（如Ｃｅ￣（３＋）、Ｐｒ￣（３＋）、Ｓｍ￣（３＋）、Ｅ...     

Dy^3＋在（LaO）3BO3和（GdO）3BO3中的光致发光

研究了Ｄｙ＾３＋在（ＬａＯ）３ＢＯ３和（ＧｄＯ）３ＢＯ３中的光致发光;探讨了基质晶体结构、稀土离子ＲＥ＾３＋的电荷半径比（Ｚ／ｒ）和Ｄｙ＾３＋含量对（Ｄｙ＾３＋）发光强度及发光颜色的影响;分析了（ＧｄＯ）３ＢＯ３中Ｂｉ＾３＋对Ｄｙ＾３＋发光的敏化作用及Ｄｙ＾３＋４Ｆ９／２→＾６Ｈ１３／２超灵敏跃迁发射的自身浓度猝灭机理。     

Ca3La3（BO3）5基质中Tb^3＋的光致发光

在２５４ｎｍ紫外光激发下，研究了Ｃａ３Ｌａ３（ＢＯ３）５基质中Ｔｂ＾３＋的激发光谱，发光光谱、发光寿命与Ｔｂ＾３＋的４ｆ＾８→４ｆ＾７５ｄ＾１允许迁的激发带位于２３０～２６０ｎｍ光谱区，故Ｔｂ＾３＋能很好地吸收激活能而发光，成为一种有发展前途的绿粉。Ｃｅ＾３＋可能与Ｔｂ＾３＋争夺激活能而猝灭Ｔｂ＾３＋的发光，一定量的Ｄｙ＾３＋能敏化Ｔｂ＾３＋的发光。     

SrS:Ce3+,K+荧光体的微波辐射合成法及对发光特性的影响

本文首次用微波辐射法（ＭｉｃｒｏｗａｖｅＲａｄｉａｔｉｏｎＭｅｔｈｏｄ，简称ＭＲＭ）合成了纯的ＳｒＳ基质和ＳｒＳ∶Ｃｅ３＋，Ｋ＋蓝色荧光化合物，用ＸＲＤ测定了它们的晶体结构，系统考察了不同浓度的Ｃｅ３＋离子对发光性能的影响。实验发现，微波辐射能使Ｃｅ３＋在ＳｒＳ基质晶格中均匀扩散，并能提高激活剂的掺入量，阻止Ｃｅ３＋离子的簇集，延缓Ｃｅ３＋离子对的形成，从而能得到晶相纯、粒度均匀和发光效率高的ＳｒＳ∶Ｃｅ３＋，Ｋ＋蓝色荧光体。     

降低Nd_2O_3中杂质Sm_2O_3的工艺研究

在工业生产实践中，对Ｎｄ－Ｓｍ分组采用大捞大洗和加氨水强化萃取分离的工艺方法实现了一步萃取法除去Ｌａ３＋Ｃｅ３＋Ｐｒ３＋Ｎｄ３＋萃余液中Ｓｍ３＋的目的，经六个月运行，产品Ｎｄ２Ｏ３中杂质Ｓｍ２Ｏ３含量稳定在０．０３％以下。     

溶胶-凝胶法合成Y_2O_3-SiO_2∶Eu~(3 ),Bi_(3 )发光体及发光特性研究

采用溶胶－ 凝胶法低温合成了Ｙ２Ｏ３ － ＳｉＯ２ ∶Ｅｕ３＋ ,Ｂｉ３＋ 发光体,研究了烧结温度、Ｅｕ３＋ 及Ｂｉ３＋ 浓度、Ｙ２ Ｏ３ 与ＳｉＯ２ 的配比对发光强度的影响。通过Ｘ射线粉末衍射、热重及差热分析,研究了由凝胶至发光晶体的转变,通过激发光谱和发光光谱的测试,讨论了材料的发光特性及Ｂｉ３＋ 对Ｅｕ３＋ 的敏化作用。     

烧结BaTiO3—CaSnO3对玻璃氧化物介电性能的影响

本文研究了铁电陶瓷ＣａＴｉＯ３－玻璃氧化物组成厚膜的烧结性能。添加有１０％（重量百分比）ＣｄＯ－Ｂ２Ｏ３－ＳｉＯ２玻璃系的ＢａＴｉＯ３能够在比不具流动性的ＢａＴｉＯ３系烧结温度低３００－５００℃的条件下烧结。在实验中分别测定了具有流动性和不具流动性的ＢａＴｉＯ３系的介电常数，介质损耗和居里温度。     

氟碳铈矿热分解行为的研究

采用ＸＲＤ法分析了不同温度下氟碳铈矿焙烧分解产物的组成，探讨了氟碳铈矿的热分解过程。试验结果表明氟碳铈矿的热分解是分步进行的。首先（Ｃｅ，Ｌａ）ＣＯ３Ｆ分解成（Ｃｅ，Ｌａ）ＯＦ；升高焙烧温度，（Ｃｅ，Ｌａ）ＯＦ发生相分解，生成Ｃｅ０．７５Ｎｄ０．２５Ｏ１．８７５和（Ｃｅ，Ｐｒ）Ｌａ２Ｏ３Ｆ３两相；随着焙烧温度的继续升高，（Ｃｅ，Ｐｒ）Ｌａ２Ｏ３Ｆ３可分解为ＬａＦ３、Ｃｅ２Ｏ３、ＰｒＯ１．８３等相。焙烧过程中Ｃｅ３＋、Ｐｒ３＋氧化为四价，没有明显的脱氟行为。     

BaYB_9O_（16）中Ce_（3＋）→Dy_（3＋）的能量传递机理

本文研究了在紫外光激发下，Ｃｅ３＋、Ｄｙ３＋共掺杂的ＢａＹＢ９Ｏ１６发射光谱，激发光谱以及发光强度随组成而变化的规律。结果表明，Ｃｅ３＋对Ｄｙ３＋发光有较强的敏化作用，Ｃｅ３＋→Ｄｙ３＋的能量传递效率达９０％以上，能量传递机理为电偶极—电偶极相互作用的共振传递。     

CaTiO_3∶Pr~(3+)的合成及发光特性

本文采用高温团相反应合成TCaTiO3∶Pr3+红色发光材料、报道了Pr3+激活的CaTiO3的光谱特征及长余辉特性，并与CaS∶Eu的光谱特性及长余辉进行了比较。CaTiO3∶Pr3+将是一种具有广泛用途的新材料     

Effect of different dopants on the long lasting phosphorescence behavior of CaTiO_3：Pr~（3＋）

In order to improve the luminescence properties of CaTiO3:Pr3+, a series of CaTiO3:Pr3+, such as CaTi0.97Nb0.03O3:Pr3+, Ca0.8Zn0.2TiO3: Pr3+, Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ and B3+-doped Ca0.8Zn0.2Ti0.97Nb0.03O3: Pr3+ were prepared through conventional solid state reaction method. The results of the photoluminescence excitation and emission spectra showed that all the samples emitted red phosphorescence at 612 nm originating from 1D2 to 3H4 emission of Pr3+ under the 337 nm excitation. When examined by the X-ray diffraction (XRD), all the samples presented a predominant phase of CaTiO3 (JCPDS# 42-423) except Zn2+-doped samples which also revealed another phase of Zn2Ti3O8 (JCPDS# 73-579). The results of the afterglow decay curves showed that co-doping Zn2+ ions, Nb5+ ions or adding a small amount of B3+ into Ca0.8Zn0.2Ti0.97Nb0.03O3:Pr3+ were effective in improving the photoluminescence properties of CaTiO3:Pr3+ phosphor. Thermoluminescence results showed that the trap existing in all the samples was the same as in CaTiO3:Pr3+ and doping singly Nb5+ or Zn2+ hardly changed the trap depth but co-doping Nb5+ and Zn2+ could modify the trapping level from 0.63 to 1.26 eV distinctively. In addition, adding a certain amount of B3+ into CTO-PZN could also deepen the trap depth.     

(Zn, Ca) Solid-Solution Behavior and Its Effect on Luminescence Properties in Ca1- xZnx TiO3: 0.002Pr3+ Phosphors

Nominal composition of Ca1 - xZnxTiO3: 0. 002Pr3 ( x = 0. 000 ～ 0. 200) phosphors were prepared by conventional solid reaction route. XRD and PL measurements were used to investigate the solid-solution structure and luminescence properties of Zn-doped Ca1- xZnxTiO3:0. 002Pr3 phosphors. The effect of solid-solution structure formed by substitution between Ca2 and Zn2 ions on the luminescent properties was analyzed. The results reveal that, with the increase of Zn substitution content below 0.010, lattice parameters and the intensity of excitation peak at both 260 and 330 nm as well as the corresponding 610 nm emission intensity are monotonously decreased quickly in a similar tendency. Also, the evolution of luminescence intensity and crystal cell parameters against Zn doping concentration are in good agreement.Above results are closely related with the structure change within Ca1- xZnxTiO3:0. 002Pr3 solid-solution phase formed by the Zn ions substitution for the Ca sites. Present study reveals that the solid-solution structure formed by substitution between Ca2 and Zn2 ions has significant effect on the luminescence properties of single phase Ca1- xZnxTiO3:0.002Pr3 phosphors.     

Enhancement of luminescence and afterglow in Ca0.8Zn0.2TiO3:Pr3+ by Nb5+ substitution for Ti4+

Nb5+ doped Ca0.8Zn0.2TiO3:Pr3+ red long afterglow phosphors were synthesized by solid-state reaction methods. X-ray diffraction, photoluminescence spectroscopy and thermally stimulated spectrometry were used to investigate the effects of Nb5+ content on the crystal characteristics and luminescent properties of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ phosphors. The results showed that the addition of a small quantity of Nb5+ had negligible effect on the crystal characteristics of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+, but it could change the trapping parameters (the depth of trap, frequency factors and the concentration of trapped charges at t=0) of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ phosphors, and then led to the enhance-ment of red fluorescence and phosphorescence at 612 nm originating from 1D2→3H4 transition of Pr3+. Both of the red fluorescence intensity and afterglow time reached the largest values in the sample of Ca0.8Zn0.2Ti1-xNbxO3:Pr3+ with x=0.05. The afterglow time of Ca0.8Zn0.2Ti0.95Nb0.05O3:Pr3+ phosphors lasted for over 24 min (≥1 mcd/m2) when the excited source was cut off.     

Synthesis and luminescent properties of Pr-doped Lu3Al5O12 translucent ceramic

Lutetium aluminum garnet (LuAG) precursors doped with different Pr3+ concentration (0.25at.%, 0.5at.%, 1.0at.%, 3.0at.%, 5.0at.%) were synthesized via a co-precipitation method using ammonium hydrogen carbonate as precipitant. The phase evolution and mor-phology of the precursor were characterized with X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The resultant LuAG:Pr3+ powder was sintered into translucent ceramic without any additives in vacuum at 1150℃ and then in nitrogen atmosphere at 1700℃. Photohiminescence spectra of LuAG:Pr3+ powder and ceramic were measured at room temperature in vacuum ultraviolet (VUV) and ultraviolet (VU) region. For the 5d-4f transition of Pr3+ ions, dominant emission of ceramic samples peaking round 311 nm had higher lumines-cence intensity. And the host absorption in ceramic samples was not as intensive as that in powder samples. The luminescent intensity of LuAG:Pr3+ varied with the Pr3+ contents and the quenching concentration was about 1.0at.% for ceramic and 3.0at.% for powder, which was much higher than 0.24at.% for LuAG:Pr3+ single crystals. This phenomenon showed that the ceramic had some superiority over single crystals.     

含钛高炉渣中钙钛矿转化为假板钛矿的研究

对钙钛矿(CaTiO_3)硫酸化分解,使钛组分转化为假板钛矿(Fe_2TiO_5)的反应体系进行分析,结果表明,采用在CaTiO_3/Fe SO4体系中通入SO_2+O_2混合气体的方法可以将钛组分一步转化为假板钛矿。基于此,考察了反应温度、配料比、气相中SO_2浓度以及反应时间等因素对硫酸化转化的影响。研究表明,在反应温度1 473 K、SO_2浓度为25%(体积分数)、反应时间120 min、CaTiO_3/Fe SO_4摩尔比1∶2.1条件下,钙钛矿中92%的钛组分可以转化成为假板钛矿;钙钛矿硫酸化分解机理随温度而变化,在温度为973~1 373 K时,钙钛矿是按照CaTiO_3+SO_2+1/2O_2=Ca SO4+TiO_2进行分解,而在1 473 K时,钙钛矿是按照CaTiO_3+SO_2+1/2O_2+Fe_2O_3=Ca SO4+Fe_2TiO_5进行分解。     

Gaseous Penetration of Pr into PbTiO3 Ceramics and Their Electric Properties

PbTiO3ceramicsisatypicalferroelectricmaterialwithperovskitestructure .TheuniquepropertiesofPbTiO3ceramicsmakeitusefulforavarietyofappli cations .Forexample ,itisaverygoodcandidateforpiezoelectricapplicationsathigh temperatureinhighsensibility[1,2 ] .Inrecentyears ,studiesondopedPbTiO3ceramicshavereceivedconsiderableattention .ThemodifiedPbTiO3ceramicsdopedwithCa2 ,Sm3 ,Y3 etcimprovedpropertiesincludingreducedCuriestemperature ,degradedtetragonaldistortionde greeandimprovedprocessabil…     

Luminescence characteristics of Ca_4YO(BO_3)_3 doped with Bi~(3+),Dy~(3+) and Pr~(3+) ions

The photoluminescence(PL) properties of Ca4YO(BO3)3 doped with Bi3+,Dy3+,and Pr3+ ions were investigated.These compounds were prepared using a typical solid-state reaction.The excitation and emission spectra were measured using a spectrofluorometer.For Ca4YO(BO3)3:Bi3+,the excitation spectrum showed the bands at about 228,309,and 370 nm which correspond to the 1S0→1P1 transition and the 1S0→3P1 transition of Bi3+ ions.The emission band at 390 nm corresponded to the 3P1→1S0 transition of Bi3+ ions.For Ca4YO(BO3)3:Bi3+,Dy3+,energy transfer occurred from Bi3+ to Dy3+ somewhat.In Ca4YO(BO3)3:Bi3+,Dy3+,Pr3+,the excitation band at 367 nm was enhanced obviously due to the energy migration from Bi3+ to Pr3+,which converted efficiently the emission of semiconductor InGaN based light-emitting diode(LED).Therefore,the emission of Dy3+ ions was enhanced due to the energy migration from the process of Bi3+→Pr3+→Dy3+.It resulted in the good color rendering.     

HPMBP和DAM协同萃取Ln~(3 )的研究

研究了１－苯基－３－甲基－４－苯甲酰基吡唑酮－５（ＨＰＭＢＰ）和二安替吡啉甲烷（ＤＡＭ）的氯仿溶液从硝酸介质中对Ｌｎ３＋（Ｌｎ＝Ｌａ，Ｐｒ，Ｎｄ，Ｇｄ）的协同萃取，测定了其半萃取ｐＨ值，结果分别为４．３８（Ｌａ３＋）、３．９７（Ｐｒ３＋）、３．９２（Ｎｄ３＋）和３．８２（Ｇｄ３＋）。通过斜率法确定了协萃合物的组成为Ｌａ（ＰＭＢＰ）３（ＤＡＭ），并合成了固态萃合物。     

Luminescent properties of praseodymium doped Y_2O_3 and LaAlO_3 nanocrystallites and polymer composites

Luminescent properties of Y2O3 and LaAlO3 nanopowders doped with Pr3+ ions and PMMA-based composite materials doped with these powders were reported.The set of active nanopowders differing in praseodymium ions concentration was prepared using sol-gel method and carefully characterized with respect to emission properties in the visible spectral range.In particular,the excitation and emission spectra were measured together with fluorescence decay profiles and the differences between optical properties of thes...