Photorefractive Properties of Potassium Lithium Niobate Crystals with CeO2 and Nd2O3

KLN and Ce：Nd：KLN crystals were gown by Czochralski method and polarized into single ferroelectrics domain along c-axis. The properties of KLN and Ce：Nd：KLN crystals, such as Curie temperature, Raman spectra, exponential gain coefficient （Г） and thin crystal sheet effect, were measured. The results showed that the two spectra resembling Ce：Nd：KLN crystal were of tetragonal tungsten bronze structure, the exponential gain coefficient of Ce：Nd：KLN crystal was higher than that of KLN crystals and Ce：Nd：KLN crystal had thin crystal sheet effect, for its exponential gain coefficient increasing with crystal sheet thinning. The thin crystal sheet effect of Ce：Nd：KLN crystal was also discussed.     

Synthesis and Characteristic Study on Complexes of Europium（Ⅲ） and Maleic Acid Doped with Non-Fluorescent Ions

Complex of europium （Ⅲ） with maleic acid, and binuclear complexes of europium（Ⅲ）with maleic acid doped with non-fluorescent ions gadolinium, lanthanum and yttrium, were synthesized. The compositions and structures of complexes were characterized with elemental analysis, single crystal X-ray diffraction, IR and DSC-TG. Fluorescent properties were studied with fluorescence spectrum. The results indicated that the strongest fluorescent complexes were obtained when the ratio of europium and non-fluorescent ion was 8：2. The order of Eu^3＋ fluorescence strengthened by three doped rare earths was Gd^3＋ 〉La^3＋ 〉Y^3＋     

Spectral Properties and Upconversion Luminescence of Er^3＋, yb^3＋： BaWO4 Crystal

The optical quality of Er^3＋, yb^3＋： BaWO4 crystal was gown by Czochralski method. Absorption spectra were measured and energy levels were assigned. According to Judd-Ofelt theory, the spectral strength parameters of Er^3＋ ion were fitted to beΩ2 =0.3926 x 10^-20 cm^2, Ω4 =0.0721×10^-20 cm^2, Ω6 =0.0028 ×10.20 cm^2. Emission peaks centered at around 523,544 and 670 nm were observed under 334 nm He-Cd laser excitation and emission peaks centered at 1001 and 1534 nm were detected under 976 nm laser excitation. Strong green emission was also observed when the crystal was pumped with 808 nm and 976 nm laser. The mechanisms of frequency upconversion and sensitization were analyzed.     

Synthesis and Upconversion Luminescence of LaF3 ： Yb^3＋ , Er^＋/SiO2 Core/Shell Microcrystals

LaF3：Yb^3＋ , Er^＋ microcrystals were synthesized by a hydrothermal method, and then, the LaF3： Yb^3＋ , Er^＋ microcrystals were coated with silica. Phase identification of LaF3： Yb^3＋ , Er^＋ and LaF3： Yb^3＋ , Er^＋/SiO2 was performed via XRD. The TEM image showed that the size of LaF3： Yb^3＋ , Er^＋ was 150 nm and LaF3： Yb^3＋ , Er^＋/SiO2 presented clearly a core/shell structure with 20 nm shell thickness. The upconversion spectra of LaF3： Yb^3＋ , Er^＋ and LaF3： Yb^3＋ , Er^＋/SiO2 in solid state and in ethanol were studied with a 980 nm diode laser as the excitation source. The upconversion spectra showed that the silica shell had little effect on the properties of fluorescence of the LaF3：Yb^3＋ , Er^＋ microcrystals. At the same time, the green luminescence photo of LaF3： Yb3＋, Er3＋/SiO2 in the PBS buffer was obtained, which indicated that the LaF3： Yb^3＋ , Er^＋/SiO2 could be used in biological applications.     

Photoluminescent and Electroluminescent Properties of Ligand Emitting y^3＋, La^3＋, Gd^3＋ and Lu^3＋ Complexes

The photolumineseent (PL) and eleetroluminescent (EL) properties of a series of ligand emitting rare earth complexes (including y^3 , La^3 , Gd^3 and Lu^3 ) were systematically studied. These complexes have the same anionic ligand, 1-phenyt-3-methyl-4-isobutyryl-5-pyrazoloneate (PMIP), and three neutral ligands, triphenyl phosphine oxide(TPPO), 2, 2‘-dipyridine (Bipy) and phenanthroline (Phen). Measured with 60 nm thin film of these complexes vaporized in vacuum on quartz substrates, a good regularity in the PL properties was observed. For rational comparison, the same structural EL devices based on these complexes, ITO/PVK (40 nm)/the complex (80 nm)/Mg: Ag (200 nm)/Ag (100 nm), were fabricated. Excluding the exeiplex emission happens, the EL luminance usually increases with the increasing of PL efficiency.     

Solution-Phase Synthesis and Characterization of Perovskite LaCoO3 Nanocrystals via A Co-Precipitation Route

A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LaCoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LaCoO3 products obtained at different calcining temperatures were investigated.     

Synthesis, Electrical and Magnetic Properties of Fe304 Doped by Dy^3＋

The Dy^3＋ -doped Fe3O4 samples were synthesized by sol-gel method, and the effects of dopant on the electrical and magnetic properties were investigated. According to XRD analysis, the high concentration doping of dysprosium ions in Fe3O4 can not be obtained due to the difference of ionic radius, and Fe^3 ＋ ions are replaced by only a small amount of dysprosium ions. The magnetic property was characterized by VSM. The substitution results in the change of saturation magnetization, which may be due to the complex effects of increasing magnetization resulted from Dy^3＋ substitution and decreasing magnetization resulted from the impurity. The electrical property was characterized by four-probe method. With the increasing eoped content, magnetoresistance also increases, then decreases, and increases again. The spin-polarization of doped samples is lower than that of Fe3O4. Lower spin-polarization results in lower tunneling magnetoresistance. Fortunately, barrier was obtained by the second phase at the same time when sample was synthesized. The increase of appropriate barrier height leads to the change of tunneling magnetoresistance.     

Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole

2 ｍｅｒｃａｐｔｏｂｅｎｚｏｔｈｉａｚｏｌｅｗａｓｆｉｒｓｔｒｅｐｏｒｔｅｄｂｙＨｏｆｍａｎｎ[1 ] ｉｎ 1 887.Ｉｔｈａｓｂｅｅｎｕｓｅｄａｓａｎａｃｃｅｌｅｒａｔｏｒｉｎｔｈｅｖｕｌｃａｎｉｚａｔｉｏｎｏｆｒｕｂｂｅｒｆｏｒｍａｎｙｙｅａｒｓ .Ｔｏｄａｙｉｔｉｓｓｔｉｌｌｂｅｉｎｇｕｓｅｄａｓａｍａｉｎａｃｉｄｉｃａｃｃｅｌｅｒａｔｏｒｉｎｒｕｂｂｅｒｉｎｄｕｓｔｒｙ .Ｂｕｔｉｔｈａｓｄｉｓａｄｖａｎｔａｇｅｓｏｆｖｕｌｃａｎｉｚａｔｉｏｎｒｅｖｅｒｓｉｏｎａｎｄｅａｓｙｓｃｏｒｃｈ[2 ] ｗｈｅ…     

Synthesis and Properties of Rare Earth Complexes with 3-Ferrocenyl-5-Phenyl-Pyrazoline-1-Dithiocarbamate

Sodium 3-ferrocenyl-5-phenyl-pyrazoline-1-dithiocarbamate (FPPD) reacts with anhydrousrare earth chlorides in absolute ethanol to give 14 new complexes.The results of elemental analysis show thatthe compositions of the complexes are RE(FPPD)_3·nH_2O(RE=La,Pr～Lu and Y;n=3).The ligand andits complexes have been characterized by infrared spectroscopy,UV-visible absorptionspectroscopy,~1H-NMR spectra,thermal analysis and molar conductivity measurement.     

Synthesis, Characterization and Properties of Lanthanide Nitrate Complexes with Isonicotinoyl Hydrazone

Ｔｈｅｄｅｓｉｇｎａｎｄｓｙｎｔｈｅｓｉｓｏｆｓｔａｂｌｅｌａｎ ｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓａｒｅｏｆｇｒｅａｔｉｍｐｏｒｔａｎｃｅｆｏｒｔｈｅｉｎｖｅｓｔｉｇａｔｉｏｎｏｆｔｈｅｐｒｏｐｅｒｔｉｅｓａｎｄａｐｐｌｉｃａ ｔｉｏｎｓｏｆｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓ .Ｍａｃｒｏｃｙｃｌｉｃｏｒａｃｙｃｌｉｃｌｉｇａｎｄｓｗｉｔｈｍｕｌｔｉｄｅｎｔａｔｅｄｏｎｏｒａｔｏｍｓｕｓｕａｌｌｙｆｏｒｍｓｔａｂｌｅｃｏｍｐｌｅｘｅｓｗｉｔｈｌａｎｔｈａｎｉｄｅｃａｔｉｏｎｓ .Ｔｈｅｓｉｚｅｏｆ…     

Synthesis and Photoluminescence Properties of Rare Earth Complexes with 3-Allyl-2, 4-Pentanedione

In order to combine the merits of rare earth organic complexes with excellent material performances of polymers,a polymerizable chelating agent, 3-allyl-2, 4-pentane dione (APD), was synthesized by phase transfer catalysis and its rare earth complexes were prepared. The compounds were characterized by EA, IR and ^1H NMR. Their UV spectra and fluorescence spectra were investigated. The effects of allyl on the luminescence properties of the complexes were studied.The results show that the sensitization of APD is changed by allyl in comparison with that of acetyl acetone (acac), and it becomes an ideal novel ligand of Eu. In addition, intramolecular energy transfer mechanism in the luminescence process in the complexes was also discussed in detail.     

Synthesis and Characterization of Lanthanide Complexes Involving Cyclopentadienyl and Benzohydroximic Acid Ligand

Ｉｎｇｅｎｅｒａｌ,ｈｙｄｒｏｘｉｍｉｃａｃｉｄｓ (ＲＣＯＮ ＨＯＨ)ａｒｅｗｅａｋｏｒｇａｎｉｃａｃｉｄｓ .ＴｈｉｓｃｌａｓｓｏｆｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓｃｏｎｔａｉｎｉｎｇｔｈｅｒｅａｃｔｉｖｅｇｒｏｕｐＣＯＮＨＯＨ ,ｋｎｏｗｎａｓｔｈｅｈｙｄｒｏｘｉｍｉｃａｃｉｄｓ,ｈａｖｅｂｅｅｎｗｉｄｅｌｙｓｔｕｄｉｅｄｂｙｏｒｇａｎｉｃｃｈｅｍｉｓｔｓ.Ｔｈｅｈｙｄｒｏｘｉｍｉｃａｃｉｄｓａｒｅｃｈｅｌａｔｅｌｉｇａｎｄｓｆｏｒｍａｎｙｍｅｔａｌｓ .Ｔｈｅｙａｒｅｗｉｄｅｌｙｕｓｅｄａｓｃｈｅｌ…     

Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2''-Bipyridine

The two compounds of [Ln(2-FBA)3·2,2'-bpy]2 (2-FBA=2-fluorobenzoato, 2,2'-bpy=2,2'-bipyridine, Ln=Eu(1), Dy(2)) were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoclinic system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2'-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. 5D0→7Fj (j= 1～4) transition emission of Eu3 ion was observed.     

Synthesis and Application of Lanthanide Complexes with Schiff Base of Pridoxylidence-Glycine

Ｔｈｅｈａｒｍｆｕｌｎｅｓｓｏｆｈｅａｖｙｍｅｔａｌｅｌｅｍｅｎｔｓｏｎｐｌａｎｔｓｉｓｏｎｅｏｆｔｈｅｓｅｒｉｏｕｓｅｎｖｉｒｏｎｍｅｎｔａｌｐｒｏｂｌｅｍｓｏｆｔｈｅｍｏｄｅｒｎｗｏｒｌｄ .Ｉｎｒｅｃｅｎｔｙｅａｒｓ ,ｔｈｅｓｔｕｄｙｏｎｔｈｅｍｉｓａｌｓｏｏｎｅｏｆｖｅｒｙａｃ ｔｉｖｅｒｅｓｅａｒｃｈｐｒｏｊｅｃｔｓｉｎｐｌａｎｔｐｏｌｌｕｔｉｏｎｅｃｏｌｏｇｙｆｉｅｌｄｓ[1～ 6 ] .ＬａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｗｉｔｈｔｈｅＳｃｈｉｆｆｂａｓｅａｒｅａｃｌａｓｓｏｆｃｏｍｐｏｕ…     

Effects of Nd, Sm, Gd, Dy, Er Dopant on Electrical Properties of BaTiO3 Ceramics

BaTiO3 ceramics doped with various quantities of Nd2O3, Sm2O3, Gd2O3, Dy2O3 and Er2O3 were prepared respectively ( the adulterate concentrations were 0. 001,0. 002, 0. 003, 0.005, 0. 007 mol fraction) through a sol-gel method and their electrical properties were researched. It is found that each adulteration of Nd2O3, Sm2O3 Gd2O3,Dy2O3 and Er2O3 all can make the resistivity of BaTiO3 ceramics decline , especially Sm2O3 and Gd2O3. When the addition of Sm2O3 is 0. 001 mol, the resistivity is the smallest, declining from 4.0 × 1012 to 6.5 × 103 Ω different kind of rare earth exhibits different regularity. The grain resistance of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 exhibits a NTC effect, at the same time the grain boundary resistance has a PTC effect, and the grain boundary resistance is much larger than the grain resistance, so the PTC effects of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 originate from the grain boundary. The additions of Nd2O3 , Gd2O3 or Er2O3 make the dielectric constant and the dielectric loss of BaTiO3 ceramics change evidently, especially Nd2O3. The dielectric constant is larger than that of pure BaTiO3 ceramics, on the other hand, the dielectric loss is much lower, which is useful in capacitor fields.     

稀土锗钨钼杂多配合物的合成及表征

合成了十二种稀土锗钨钼酸根多元杂多配合物。利用元素化学分析和ICP相结合方法、IR等手段对配合物进行了初步表征。     

Synthesis of Long Afterglow Phosphor CaAl2Si2O8:Eu2+, Dy3+ via Sol-Gel Technique and Its Optical Properties

The long afterglow phosphor CaAl2Si2O8:Eu2 , Dy3 was prepared by a sol-gel method. The sol-gel process and the structure of the phosphor were investigated by means of X-ray diffraction analysis (XRD). It is found that the single anorthite phase formed at about 1000 ℃, which is 300 ℃ lower than that required for the conventional solid state reaction. The obtained phosphor powders are easier to grind than those of solid state method and the partical size of phosphor has a relative narrow distribution of 200 to 500 nm. The photoluminescence and afterglow properties of the phosphor were also characterized. An obvious blue shift occurs in the excitation and emission spectra of phosphors obtained by sol-gel and solid state reaction methods. The change of the fluorescence spectra can be attributed to the sharp decrease of the crystalline grain size of the phosphor resulted from the sol-gel technique.