Ca3La(BO3)3中Dy3+的光致发光

研究了Ca3La(BO3)3基质中Dy^3 的发射光谱和激发光谱。结果表明，强的激发峰值为351nm、367nm和386nm；Dy^3 的488nm和578nm发射的最佳浓度均为xDy=0．03；Dy^3 发射的黄光和蓝光强度比(用Y／B表示)随Dy^3 浓度的增加而逐渐增大；Dy^3 的^4F9/2→^6H15/2、^6H13/2跃迁发射的浓度猝灭机理均为电偶极-电偶极相互作用；同时还探讨了Ce^3 对Dy^3 发光的敏化作用。     

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。     

Photoluminescence of Dy^3＋ Ions in Ba3La（B03）3

The photoluminescence of Dy^3 doped and Dy^3 , Ce3 codoped in Ba3La(BO3)3 were studied. The dependence of the charge-to-radius ratio (z/r) for RE^3 (RE=La,Ce), the Ce^3 , Dy^3 content on the emission intensity and the yellow to blue intensity ratio (Y/B) of Dy^3 were investigated too. The results obtained indicate that Ce^3 can sensitize the luminescence of Dy^3 .The optimum concentration of Dy^3 in Ba3La(BO3)3 is XDy=0.06. According to the dependence of the concentration of Dy^3 in Ba3La(BO3)3 under the excitation of 350 nm, it is confirmed that the mechanism of concentration selfquenching of Dy^3 4F9/2→6H15/2, ^6H13/2 transition is electric dipole-quadrupole interaction.     

Luminescence Properties of （ Y, Gd） Al3 （BO3） 4 ： Eu^3＋ under VUV excitation

(Y, Gd)Al3 (BO3)4:Eu^3 samples were prepared by the conventional solid state reaction. The XRD results indicate that the crystal symmetry is low. The excitation spectrum is composed of two broad bands centered at about 170 and 250 nm respectively. In the emission spectra, the peak wavelength is about 616 nm under 147 nm VUV excitation. The luminescent chromaticity coordinate and the relative intensity change along with Gd^3 mole concentration in the range of 0.15 to 0.85 mol (and Eu^3 mole concentration, 0.02 to 0. 1 mol). The correlative data show that the concentration quenching occurs when the Eu^3 mole concentration ranges from 0.02 to 0.1 mol, and the Gd^3 →Gd^3 , Gd^3 →Eu^3 and host→Eu^3 , Gd^3 energy transfers exist, and Gd^3 mole concentration influences Eu^3 emission.     

Synthesis of Spherical （Y, Gd） BO3 ： Eu^3＋ Phosphor Using W/O Emulsion System

Spherical （Y, Gd）BO3：Eu^3＋ phosphor particles with a narrow size distribution（2 -4 μm） was obtained by firing the Y-Gd-Eu-BO3 precursor prepared in a W/O style emulsion system. In the W/O emulsion system, kerosene, used as oil phase, was mixed with Span 80 and Tween 80 compounds which were employed as the emulsifier with an HLB （hydrophile-lipophile balance） value of 5.2- 5.3. Both rare earths （Y, Gd and Eu） nitrate and boric acid solution or ammonia solution were used as aqueous phase. The synthesis conditions, such as emulsion composition, emulsifying style, precipitation reaction process, reaction temperature, morphology control, and so on, were investigated, and the optimum synthesis conditions for preparing spherical （Y, Gd）BO3：Eu^3＋ phosphor was obtained. The phosphor was characterized by XRD, SEM, laser particle size analysis, emission and excitation spectrum under vacuum ultraviolet （VUV）, and so on. The phosphor synthesized using the water-in-oil emulsion method with median diameter （D50） of 2 - 4 μm shows agreeable photoluminescence （PL） property and sphericity. The main emission peak appears at about 593 nm, which corresponds to ^5D0→^7F1 transition （magnetic-dipole transition） of the Eu^3＋ ion. The cell parameters and powder diffraction data were indexed. The structure of the phosphor belongs to the hexagonal system with space group P63/m.     

掺Ce~（3＋）、Tb~（3＋）的四硼酸铝钇的发光特性

本文采用固相反应法合成了一系列掺Ｃｅ￣（３＋）、Ｔｂ￣（３＋）的四硼酸铝钇（Ｙ＿（１－ｘ－ｙ）Ｃｅ＿ｘＴｂ＿ｙＡｌ（ＢＯ＿３）＿４）磷光体。测定了它们的结构、属于三方晶系、空间群Ｒ＿（３２）、Ｌｎ￣（３＋）离子处于六个氧形成的三棱柱中。测定了磷光体中Ｃｅ￣（３＋）、Ｔｂ￣（３＋）和Ｃｅ￣（３＋）－Ｔｂ￣（３＋）共掺时的光谱，观察到Ｃｅ￣（３＋）、的Ｓｔｏｋｅｓ位移相当小（～１７００ｃｍ￣（－１））、Ｔｂ￣（３＋）的能级劈裂较明显和Ｃｅ￣（３＋）能将能量传递给Ｔｂ￣（３＋），测定了磷光体中Ｃｅ￣（３＋）、的荧光寿命，探讨了Ｃｅ￣（３＋）－Ｃｅ￣（３＋）之间的能量传递。     

New Green Phosphors Ba（1-x）SrxZr（BO3）2 Doped with Tb^3＋ for PDP Applications

Thephosphorsusedinplasmadisplaypanel(PDP)deviceshouldemitvisiblelightundervacuum ultraviolet(VUV)excitationof147nmand or172nm fromXe Hegasplasma[1].Recentlylotsoftraditional lampphosphorshavebeenusedascommercialphos phorsforPDP.However,thesematerialsstill…     

Growth, Thermal and Optical Properties of Dyx Y1 - x Al3 （ BO3 ） 4 Crystal

Recently ,solid statelasersoperatingintheyel lowregionhavegainedmuchattentionbecauseoftheirimportantapplicationinmilitaryandtelecommunica tion .SomeresearcheshavedemonstratedthatDy3 canobtainyellowlaseremissionusingthe 4 F9/2 →6 H13/2 channel[1～ 3] .RareearthionsdopedYAl3(BO3) 4(YAB)crystalwasreportedtobepromisingmaterialsforlaserapplications .TheYABcrystalhashigh hardness ,isnonhygroscopicandchemicallysta ble,andonlycanbegrownbythefluxmethodbe causeofmeltingincongruently .TheYABcryst…     

A comparison of Ce~（3＋） luminescence in X_2Z（BO_3）_2（X=Ba,Sr;Z=Ca,Mg） with relevant composition and structure

The VUV-UV spectroscopic properties of Ce3+ in Ba2Mg(BO3)2,Ba2Ca(BO3)2 and Sr2Mg(BO3)2 were compared,and the relation between the energy of the 4f→5d transition of Ce3+ and the coordination environments of substituted alkaline earth ions was discussed.The chromaticity coordinates of Ce3+ activated X2Z(BO3)2(X=Ba,Sr;Z=Ca,Mg) phosphors were changeable from blue to whitish and further to green range by varying the doping concentration of Ce3+ or the types of substituted alkaline earth ions upon 172 nm excitation.     

Luminescence properties of YAl3（BO3）4 phosphors doped with Eu^3＋ ions

YAl3 （BO3）4： Eu^3＋ phosphors were prepared by the conventional solid state reaction. The phase structure and morphology were investigated by X-ray diffraction （XRD） and scanning electron microscope （SEM）. Doping YAl3（BO3）4： Eu^3＋ phosphors with concentration of Eu^3＋ ions of 0, 2, 5, 8 and 10 mol% were studied and their luminescent properties at room temperature were discussed. The excitation spectrum of Y0.95Eu0.05Al3（BO3）4 was composed of a broad band centered at about 252 nm and a group of lines in the longer wavelength region. In the emission spectra, the peak wavelength was about 614 nm under a 252 nm UV excitation. The optimal doping concentration of Eu^3＋ ions in YAl3（BO3）4： Eu^3＋ phosphors was 8 mol%.     

Large Magnetic Entropy Effect in La2／3Ca1／3MnO3

The magnetocaloric effect in the colossal magnetoresistance material La2/3Ca1/3MnO3 was studied. From the measurements of temperature dependence of magnetization in various magnetic fields, the large magnetic entropy change associated with the ferromagnetic-paramagnetie transition was discovered. This result suggests that perovskite manganites are suitable candidates as working substance in magnetie refrigeration technology.     

Eu^3＋在（GdO）3BO3中的发光特性

研究了紫外光（ＵＶ）和阴极射线（ＣＲ）激发下（ＧｄＯ）＿３ＢＯ＿３：Ｅｕ的发光特性及其光谱随组成和结构变化的规律。在这两种激发条件下，（ＧｄＯ）＿３ＰＯ＿３中的Ｅｕ￣（３＋）均能发出明亮的红色荧光。ＣＲ激发下，在加速电压１０～２０ｋＶ、电流密度１～５μＡ／ｃｍ￣２内，Ｅｕ￣（３＋）的发光亮度与电压或电流密度之间均呈良好的线性关系，并具有耐电子束轰击的能力。根据３９５ｎｍＵＶ激发下（Ｇｄ＿（１－ｘ）ＥｕｘＯ）＿３ＢＯ＿３体系中Ｅｕ￣（３＋）的５Ｄ＿１→￣７Ｆ＿１跃迁（５３５ｎｍ）及￣５Ｄ＿ｏ→￣７Ｆ＿２跃迁（６１１ｎｍ）发射强度与Ｅｕ￣（３＋）浓度的关系，证明其浓度猝灭机理分别为电偶极－电偶极相互作用和交换作用。     

Photoluminescence of SrGdGa3O7：RE（RE=Ce^3＋, Pr^3＋ ,Tb^3＋） under VUV-UV Excitation

SrGdGa3O7:RE(RE=Ce^3 ,Pr^3 ,Tb^3 ) were prepared by traditional solid-state reaction and their luminescence properties in the range of VUV-Vis were investigated. The two broad bands situated at about 177 and 217nm in excitation spectra are attributed to the host lattices absorption, and they have no considerable change when doped different rare earth ions. The f-d transitions of Pr^3 and Tb^3 calculated by the formula gathered by Dorenbos were compared to the experimental results. The excitation spectra also show the sharp Gd^3 excitation line at about 274 nm pointing to an efficient energy transfer from Gd^3 to Pr^3 and Tb^3 . All of the emission spectra present the characteristic emissions of rare earth ions when excited by VUV and UV.     

Self-Assembled Film of Tb^3＋ and Poly （3-Thiophene Acetic Acid） via Layer-by-Layer Complexation Technique and Its Photoluminescence

The layer-by-layer complexation technique of polymer and metal ion was successfully utilized to fabricate the uhrathin muhilayer film of poly(3-thiophene acetic acid (PTAA) and Tb^3 ion by dipping the substrates alternatively in polymer and Tb^3 ion aqueous solutions. UV - vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X-ray photoelectron spectrum (XPS) confirmed the existence of Tb^3 ion. The pH of both the polymer and TbCl3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb^3 ion as well as the ligand indicating the formation of the complex.     

用P507-煤油-HCl体系从YCl3溶液中萃取分离La3+和Ca2+

在生产高纯Y2O3中,YCl3溶液中的Ca2 与La3 均可以用P507萃取分离。经萃取分离后,产品中Ca2 与La3 的质量分数分别低于7×10-6与1×10-6,符合要求。     

Synthesis and Electrical Properties of La0.6M0.4FeO3-δ （M = Ca, Sr, Ba） as Cathodes for SOFCs

Intermediate-temperature solid oxide fuel cells(IT-SOFCs) have attracted extensively attentionin re-cent years because of the potential to dramatically re-duce the cost of the materials and cell fabrication inaddition to i mprove reliability , portability and long-termperformance stability ,it has been regarded as ahigh green energyin 21st[1].However ,the experi men-tal results identifiedthat the ohmic losses of IT-SOFCslargely occurred from cathode polarization , and theknown cathode mate…     

天然高岭石类粘土矿物对Sc~（3＋）、Th~（4＋）的吸附

研究了两种天然高岭石类粘土矿物样品对Ｓｃ３＋、Ｔｈ~４＋离子的吸附等温线，用最小二乘法的关联结果表明，可以用Ｌａｎｇｍｕｉｒ、Ｆｒｅｕｎｄｌｉｃｈ和Ｔｅｍｋｉｎ吸附等温线方程来描述。粘土对Ｓｃ~３＋、Ｔｈ~４＋的吸附表现出典型的电性交换吸附特征。且对Ｓｃ~３＋具有更强的吸附能力。证明该类粘土不仅可以用来吸附富集Ｓｃ~３＋、Ｔｈ~４＋，而且可以选择适当浓度的酸溶液作淋洗剂来进行Ｓｃ~３＋、Ｔｈ~４＋的离子交换分离。     

Site Selective Excitation and Energy Transfer in LiKGdF5 Crystal Co-doped with Er^3＋ and Tb^3＋

Crystals of LiKGdF5:Er^3 , Tb^3 grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er^3 and Tb^3 ions embedded in LiKGdF5 were clearly separated. The lifetimes of the emitting levels ^4S3/2 of Er^3 and ^5D4 of Tb^3 were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb^3 to Er^3 in the crystal was then investigated via transient experiments.