Simultaneous Determination of Trace Rare Earth Elements and Other Elements in High Purity Terbium Oxide (Tb_4O_7) by ICP-AES After HPLC Separation Using P507 Resin

This article describes a new method for the simultaneous determination of trace rare earth elements (REEs) and non rare earth elements (NREEs) in high purity terbium oxide by ICP-AES after HPLC separation using P507 resin. The chromatographic separation of the analytes from the matrix using dilute nitric acid as mobile phase was studied. The experimental results showed that a favorable separation of trace metals (Cu and Gd) from the matrix (Tb) can easily be achieved by elution with dilute nitric acid within 25 min. The proposed method was applied to the determination of trace metals (Ca, Cu, Mg, Mn, Ni, Si, La, Ce, Pr, Nd, Sm, Eu and Gd) in high purity terbium oxide. The detection limits (DLs) for the analytes ranged from 0.4-4.0 μg\5g -1, and the recoveries are from 78%-105%.

Preparation, Photo and Electroluminescence Properties of Novel Rare Earth Aromatic Carboxylates

Novel soluble rare earth aromatic carboxylates were prepared. The triplet energy level of organic ligand was measured. The photoluminescence properties of the Tb 3+ and Eu 3+ aromatic carboxylates and lifetimes were investigated, which indicated that these rare earth complexes have high quantum efficiency. Because of their excellent solubility, polymer-doping rare earth carboxylates were fabricated as thin films by spin-coating method and their luminescence properties were studied. Some rare earth organic light-emitting diodes were successfully fabricated which performed high pure color. The maximum luminance of the device of ITO/PVK/PVK∶Tb(AS) 3Phen∶PBD/PBD/Al is 32 cd·m -2 at 28 V.

Crystal Structure and Fluorescent Study of a Terbium(Ⅲ) Coordination Polymer

A novel Tb（Ⅲ） coordination polymer [Tb（bpapO2）2（NO3）3]n [bpapO2 = N2,N6- bi（pyridin-2-yl）pyridine-2,6-diamine-N,N＇-dioxide-dioxide] has been synthesized and it exhibits terbium’s characteristic fluorescent emission under UV radiation of 326 nm at room temperature. X-ray structural determination indicates that each terbium（Ⅲ） ion, centered in TbO8 core, connects to three adjacent coordinate centers via a bi-dentate ligand bpapO2, forming a one-dimensional coordination polymer. The compound crystallizes in the triclinic system, space group P1, with a = 11.2271（5）, b = 11.7997（5）, c = 14.8016（6） Ⅲ, α = 72.7060（10）, β = 89.9630（10）, γ = 66.7680（10）o, Z = 2, Dc = 1.822 g/cm3, V = 1705.14（13） Ⅲ3, F（000） = 932, the final R = 0.0340 and wR = 0.0669 for 4812 observed reflections with I 2σ（I）.

Physical Properties of Liquid Terbium Measured by Levitation Techniques

To understand the nature and behavior of rare earth metals in their liquid phases, accurate values of their physical properties are essential. However, to measure their physical properties, the samples should be maintained in liquid phases for prolonged time, and this raises a formidable challenge. This is mainly explained by their high melting temperatures （e.g., 1629 K for Tb）, high vapor pressure, and the risk of melt contamination with a crucible or support. An electrostatic levitation furnace alleviated these difficulties and allowed the determination of density, surface tension, and viscosity of several metals above their melting temperature. Here, first, the levitation furnace facility and the noncontact diagnostic procedures were briefly discussed, followed by the explanation of their thermophysical property measurements over wide temperature ranges. The density was obtained using an ultraviolet-based imaging technique that allowed excellent illumination, even at elevated temperatures. Over the 1615 to 1880 K temperature span, the density measurements could be expressed as p（T） =7.84 × 10^3 -0.47 （T - Tm） （kg · m^-3） with Tm = 1629 K, yielding a volume expansion coefficient a（T） = 6.0 × 10^-5 （K^-1）. In addition, the surface tension and the viscosity could be determined by inducing a drop oscillation to a molten sample. Using this technique, the surface tension data could be expressed as σ（T） = 8.93 × 10^2 - 0.10 （T - Tm）（mN· m^-1） and those for viscosity as η（T） =0.583 exp [4.1 × 10^4/（RT）] （MPa·s） over the 1690 to 1980 K temperature range

Synthesis,Characterization and Fluorescence Properties of Europium,Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline

Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen) L3·1/2H2O; Tb (phen) L3·H2O and Tb0.5 RE0.5(Phen)L3·1/2H2O. (RE = Y3+, La3+ and Gd3+; L = biphenyl 4-carboxylic acid; phen = o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE (III ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 + is raised by inert fluorescent rare earth ions (Y3+ , Gd3+ and La3+ ), but in Tb3+ hetero-nuclear rare earth complexes the intensity of Tb3+ ions are quenched by the inert fluorescent rare earth ions.

Synthesis and Characteristic of Poly(N-vinylacetamide) Containing Terbium Ion

Poly (N-vinylacetatnide) ( PNVA) was synthesized by free radical polymerization in ethanol solution, in which alpha, alpha'-azobisisobutyronitrile was used as an initiator. Tb(III)-PNVA polymer was prepared and characterized by ultraviolet-visual (UV), fourier transform infrared (FIF-IR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. The experimental results of UV, FT-IR and XPS show that the Tb (III)-PNVA electrovalent complex is formed by electrostatic interaction between terbium (III) cation and complexible atoms of acylamino group in the pendant chain of the polymer. The fluorescence spectrum of the complex exhibits intensive characteristic emission of terbium at 490, 545 and 584 run, which are assigned to D-5(4)->F-7(6), D-5(6)->F-5(6) and D-5(4)->F-7(3) transition, indicating that there exists an efficient intermolecular energy transfer from the polymer ligand to the central rare earth ion. The emission intensity of the complex is increased with the increasing concentration of Tb (III) ion until the weight ratio of Tb (III) on to PNVA is 1.5% (mass fraction), and decreased with the further increasing concentration of Tb (III) ion, which is a typical concentration quenching behavior.

Organic Light Emitting Devices Based on Terbium Complex

Rare earth complex TbY(m-MOBA)_6(phen)_2·2H_2O was synthesized, which was first used as an emitting material in electroluminescence. The properties of monolayer device with the rate of 1000 r·min^(-1) (70 nm) and the impure concentration of 1∶5 were the best. And the highest brightness of this device reached 21.8 cd·cm^(-2) at a fixed bias of 20 V. Bright green emission can be obtained from the optimized double-layer device, and the highest EL brightness of the device reached 289 cd·m^(-2) at the voltage of 21 V.

Sol Gel Assembly and Luminescence of SiO_2/PEMA Hybrid Material Incorporated with Terbium Complex

Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.

Fluorometric Determination of Terbium by Aromatic armed 1,4,7-triazacyclononane

Terbium and N,N′,N' tri(3,5 diamino benzenesulfonyl) 1,4,7 triazacyclononane (TDABS Tacn) form a stable chelate having a 1∶1 molar ratio in dilute aqueous solution. The fluorescence property of the chelate was studied under the experimental conditions (pH 8.4 in H 3BO 3 KCl NaOH buffer, λ EX =309 nm, λ EM =374 nm). The fluorescence intensity is a linear function of concentration in the range of 5.0×10 -6 to 4.2×10 -4 mol/L for terbium. The relative standard deviation is less than ±2.0%. When tolerable amount of other metal ions were added to the solution of terbium chelate, the fluorescence intensity can be determined without interference. These results suggest that aromatic armed polyazamacrocycle can be used for the terbium determination.

Synthesis and Characterization of Terbium-Trimesic Acid Luminescent Complex in Polyvinylpyrrolidone Matrix

Tb（Ⅲ ）-trimesic acid （TMA） luminescent complexes were synthesized in the polyvinylpyrrolidone （PVP） matrix. The elemental analysis, inductively coupled plasma-atomic emission spectroscopy （ICP-AES） and fourier-transform infrared spectroscopy （FT-IR） indicated that its chemical constitution is PVP/Tb（MTA）· 4H2O. The XRD patterns showed that the complex is a new kind of crystal. The TEM image indicates that the complex is rod shaped. The rod diameter is about 200 nm, and the length ranges from hundred of nanometer to a few micrometers. In addition, the dispersity is better. TG-DTA curves indicate that the complex is thermally stable before 463℃. Photoluminescence analysis indicates that the complex emits Tb^3＋ characteristic luminescence under ultraviolet excitation.

Influence of La, Y, Gd, Cu, NH_4^+ Ions and DMSO on Luminescent Property of Terbium Complexes with Sulfosalicylate

The complex Tb(SSA)·H 2O (1) and Tb 2.5 La (SSA) 3.5 ·7H 2O (2), TbY(SSA) 2·2H 2O (3), Tb 1.5 Gd(SSA) 2.5 ·4H 2O (4), TbGd 1.5 (SSA) 2.5 ·3H 2O (5), TbGd 2.5 (SSA) 3.5 ·4H 2O (6), TbGd 3(SSA) 4·5H 2O (7), Tb 10.5 Cu 3(SSA) 12.5 ·30H 2O (8), (NH 4) 1.5 TbLa(SSA) 2.5 ·4H 2O (9), and (NH 4)Tb 2Cu(SSA) 3·6H 2O 10 (H 3SSA= sulfosalicylic acid ), were obtained by reacting ammonium sulfosalicylate with terbium chloride; or with the mixed solution of TbCl 3 and RECl 3 (or CuCl 2) (RE=La, Gd or Y). The compositions of these complexes and the fact that complexes 2～10 can be heteronuclear complexes or sosoloid from complexes and not usual mixture was confirmed by element analysis, IR, TGA and fluorescence analysis. Their luminescent properties were studied in a dimethyl sulfoxide(DMSO) solution (concentration: 1×10 -3 and 1×10 -4 mol·dm -3 ), and some infrequent results were obtained as follows: include, discovery of a synergistic effect between Tb 3+ and Cu 2+ in the 8; observation of the fluorescence quenching effect of NH 4 + in the 9 and 10; the fact that the fluorescence of the mixture of Tb(SSA) and Gd(SSA) (molar ratio 1∶1.5) is more intense than that of complex 1; and the influence of the DMSO on fluorescence enhances effect for the solutions of complexes in DMSO.

Study on Photochemical Fluorescence Enhancement of Terbium-Fleroxacin Complex

The sensitized fluorescence intensity of terbium ion can be notably enhanced when the Tb 3+ fleroxacin complex is exposed to 365 nm light. By the measurements of fluorescence spectra, phosphorescence spectra, fluorescence quantum yield and fluorescence lifetime of the system, it is proved that irradiation makes the complex undergo a photochemical reaction and produces a new terbium complex which is more favorable to intramolecular energy transfer. The mechanism of the photochemical fluorescence enhancement was discussed.

Luminescence of Terbium Complexes Incorporated into Silica Matrix

Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.

Determination of Effective Segregation Coefficient of Oxygen in Terbium During Floating Zone Refining

The effective segregation coefficient K-e of oxygen in terbium metal was deduced from a comparison of the theoretical curves with the concentration distributions found experimentally after a floating zone refining treatment. Thp result shows that K-e is equal to 1.2 which is an important parameter for floating zone refining terbium.

Luminescence of Terbium Chelates with Substituted Pyridine-2, 6-Dicarboxylic Acid Derivatives by Synergistic Effect of EDTA

Some spectral properties and luminescence intensities of Tb 3+ chelates of substituted pyridine 2, 6 dicarboxylic acids and 4 phenyl pyridine 2, 6 dicarboxylic acid analogues were measured in some solutions (H 2O and EtOH etc.) by synergistic effect of EDTA. The substitution at the aromatic ring has a significant effect upon the observed luminescence intensities, excitation wavelengths, and lifetime of the complexes. Moreover, the changes in the environment cause great variation in those properties of certain Tb 3+ chelates. The results show that some of hte chelates (4 acetaminopoxypyridine 2, 6 dicarboxylic acid, 4 ethoxypyridine 2, 6 dicarboxylic acid and 4 methoxypyridine 2, 6 dicarboxylic acid etc.) have a stronger emission and longer lifetime at room temperature and may thus be used as perfectly sensitizers in fluorescence analysis.

Synthesis and Fluorescence Properties of Europium, Terbium Doped Zn^(2+), Cd^(2+) and Cr^(3+) Complexes

Europium and terbium complexes with strong fluorescence intensity and long fluorescence lifetime were prepared. By replacing half of the europium or terbium ion with M （M = Zn^2＋, Cd^2＋, and Cr^3＋） using the doped method, and then incorporating it with 18-crown-6 ether and terephthalic acid, six heteronuclear samples EuZnLL＇Cl3·3H2O（1）, EuCdLL2＇Cl3·5H2O（2）, EuCrLL＇Cl4· 4H2O（3）, TbZnLL＇Cl3·4H2O（4）, TbCdLL＇2Cl3·4H2O（5）, and TbCrLL＇2Cl4 ·4H2O（6） （L = terephthalic acid, L＇= 18-Crown-6 ether） were obtained. The elemental analysis, molar conductivities, rare earth complexometry, Fourier Transform Infrared Spectroscopy （FT-IR）, ultraviolet （UV）, TGA, fluorescence intensity, and fluorescence lifetime of the samples were measured. The results showed that there were good luminescence properties for heteronuclear complexes （1）, （2）, （4）, and （5）, which were even stronger than those of the homonuclear complexes Eu2LL＇2Cl4·4H2O and Tb2LL＇2Cl4 ·4H2O, but the luminescence properties of EuCrLL＇Cl4·4H2O, TbCrLL＇Cl4·4H2O were very weak. A possible luminescence mechanism was suggested by the organic-inorganic doped mechanism and the law of intramolecular energy transfer.

Syntheses, characteristics and fluorescence properties of complexes of terbium with benzoic acid and its derivatives

The binary complexes of terbium with benzoic acid and its derivatives （phthalic acid, iso-phthalic acid, o-aminobenzoic acid, salicylic acid, sulfosalicylic acid） were synthesized and their compositions were identified by elemental analyses. UV, IR of the complexes were investigated. The UV spectra indicate that the complexes’ ultraviolet absorption is mainly the ligands’ absorption, but the location of peak drifts. The IR spectra show that the IR spectra of complexes are different from those of free ligands, and the band at 400500 cm-1, due to the stretching vibration of Tb—O, is absent for free ligands. The fluorescence properties were investigated by using luminescence spectroscope, the results show that all the six complexes of terbium exhibit excellent luminescence, due to the transition from the lowest excited state （）5D4 to （）7F ground state manifold, the complexes of terbium with sulfosalicylic acid have the strongest fluorescence intensity, and is stronger than o-aminobenzoic acid-terbium, whose fluorescence intensity is regarded as the strongest one in the literature, and even stronger than some phosphor of terbium.

Synthesis, Characterization and Fluorescence of Terbium(Ⅲ) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide

Three new complexes TbL3dipy （H2O）2, TbL3phen （H2O） 2 and TbL2 （TPPO） 2NO3 were synthesized （L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide）. Elemental analysis, conductivity, IR spectra, and ^1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb（Ⅲ） ion as an unidentate ligand. In ^1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at morn temperature, in which the optimum excitation wavelengths are, 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the ^5D4-^7Fj（j = 6, 5, 4, 3） transitions were observed for TbL3dipy（H2O）2（489.0, 545.0, 584.0, 620.0 nm） and TbL3phen（H2O）2（490.0, 544.0, 583.0, 620.0 nm）. Under the same conditions, only one emission band due to the ^5D4-^7F5 transition was observed for the complex TbL2（TPPO）2NO3. The emission intensity of TbL3dipy（H2O）2 is the strongest among the three complexes.

Organic Light-Emitting Devices Based on Terbium Complex

Rare earth complex with a structure of [Tb(m-MBA)_3phen]_2·2H_2O was synthesized,which was used as light-emitting material in electroluminescence. The terbium complex was dispersed in poly (N-vinylcarbazole) (PVK) as an emitting layer which is made by spin coating. Two kinds of devices were fabricated with structures: as following device Ⅰ: glass/ITO/PVK: terbium complex/PBD/LiF/Al, and device Ⅱ: glass/ITO/PVK: terbium complex/AlQ/LiF/Al. The photoluminescent (PL) and electroluminescent (EL) behaviors of the devices were investigated. Bright green emission can be obtained from optimized device Ⅱ,and the highest EL brightness of it reaches 140 cd·m (-2) at the voltage of 20 V.

Synthesis,crystal structure and characterization of one-dimension complex constructed by terbium(Ⅲ) and 2-iodobenzoate

The complex of [Tb（2-IBA）3（H2O）2]n （2-IBA=2-iodobenzoate） was prepared by solvent method from TbCl3-6H2O and 2-iodobenzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pi space group. The Tb^3＋ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb^3＋ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb^3＋ ions were linked by two bidentate-bridging 2-IBA ligands, forming 1-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, corresponding to ^5D4→^7Fj（J=6-3） transition emissions of the Tb^3＋ ion, respectively.