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1.
Reversed-phase extraction chromatography employing a Daiflon-supported HDEHP column and HCl as eluent was examined for carrier-free separation of167Tm from a photo-irradiated Yb target and also from particle-bombarded Er and Ho targets. The examination was performed with radioassays of radioactive Tm and Yb tracers and57Co--induced X-ray analysis of Er and Ho. An example of the separation of about 1 mCi of167Tm from a 100 mg irradiated Yb target enriched in168Yb and a procedure for the final preparation for medical use are described. The YbSO4 precipitation could be combined with this chromatographic separation of167Tm from a more massive Yb target of natural abundance, weighing several tens of grams. A procedure for YbSO4 precipitation is also presented in the Appendix.  相似文献   

2.
Double sulphates of rare earths with dimethylammonium, with empirical formula (CH3)2NH2Ln(SO4)2·4H2O (Ln=Tb, Dy, Ho, Er, Tm, Yb, Lu and Y), were studied by means of thermogravimetry, derivative thermogravimetry and differential thermal analysis from 20 to 700°. Quantitative gravimetric analysis was used for the determination of rare earths and sulphate. The mechanism of thermal decomposition is also suggested.
Zusammenfassung Doppelsulfate der seltenen Erden mit Dimethylammoniumionen der empirischen Formel (CH3)2NH2Ln(SO4)2·4H2O (Ln=Tb, Dy, Ho, Er, Tm, Yb, Lu und Y) wurden mittels TG, DTG und DTA im Temperaturbereich von 20–700° untersucht. Die Seltenen Erden und Sulfat wurden gravimetrisch bestimmt. Ein Mechanismus der thermischen Zersetzung wird vorgeschlagen.

, 20–700° (3)2N2Ln(S4)2·42, Ln=Tb, Dy, , Er, Tm, Yb, Lu Y. . .
  相似文献   

3.
Polycarbonate (Makrofol-N) and polystyrene thin films were irradiated with protons (3 MeV) under vacuum at room temperature with the fluence ranging from 1×1014 to 1×1015 protons cm−2. The change in optical properties, degradation of the functional groups and crystallinity of the proton-irradiated polymers were investigated with UV–vis, Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) techniques, respectively. The UV–vis analysis revealed that the optical band gap of irradiated Makrofol-N is reduced by 30% as compared to 27.5% in polystyrene at highest fluence of 1×1015 protons cm−2, owing to higher electronic energy loss of protons in Makrofol-N. The calculations of the number of carbon atoms per conjugation length, N and number of carbon atoms per clusters, M embedded in the network of polymers further revealed that Makrofol-N is more modified as compared to polystyrene on proton irradiation. FTIR results reveal the reduction in absorption intensity of the main characteristic bands of both the polymers after irradiation. The proton-irradiated Makrofol-N shows a strong decrease of almost all of its characteristic absorption bands at about 1×1014 protons cm−2. Beyond a critical dose an increase of almost all its characteristic bands are noticed, however, no such effect had been observed in polystyrene at this particular fluence. Appearance of new –OH groups was observed at the higher fluences in the FTIR spectra of both proton-irradiated polymers. XRD measurements show the decrease of the main peak intensity and the crystallite size, confirming the increase of amorphization in polymers under irradiation.  相似文献   

4.
The results of experiments on the preparation of carrier-free lanthanides from some targets irradiated in the U-120 cyclotron are presented. In the reactions151Eu(α, n)154m,154Tb,151Eu(α, 2n)153Tb,155Gd(α, 2n)157Dy,169Tm(α, n)172Lu and169Tm(α, 2n)171Lu, the isotopes154m,154+153Tb,157Dy and172+171Lu were obtained. These were seaprated by means of ion-exchange chromatography. Part II: see Ref. 2  相似文献   

5.
研究了以钌铱钛合金网和汞分别为阳、阴电极, 在无气氛保护条件下, 采用电解还原方法从铥、镱、镥硫酸盐溶液中分离提纯镱的过程. 讨论了在8 V恒电压时的电极间距、位置, 以及阴、阳极表面积对电解过程中的电流、还原率影响. 优化了电解还原过程, YbSO4产品的纯度稳定达到99.5%以上, 一次收率可达80%;提镱后母液中的铥和镥被富集4倍以上, 其中Lu含量高于50%, 十分有利于后续铥/镥分离.  相似文献   

6.
《化学:亚洲杂志》2017,12(23):3046-3052
Monodisperse YF3 and YOF porous sub‐microspheres were synthesized by using a novel sacrificing template method with amorphous Y(OH)CO3x H2O as the precursors and the template. It was found that the size and shape were well maintained, and the condensed precursor was transformed into uniform porous structures after fluoridation. By fine‐tuning the feed of the fluorine source, the final product could be converted from YF3 to YOF. A possible growth mechanism is proposed for the uniform porous YF3 structure and the porous yolk–shell‐like YOF structure. The luminescence properties showed that the as‐synthesized YF3:Ln3+ (Ln=Eu, Tb, Ce, Ce/Tb, Yb/Er, Yb/Ho, and Yb/Tm) products exhibited strong multicolor emissions, which included down‐/upconversion and energy‐transfer processes. Additionally, YOX (X=Cl and Br) could be obtained if a different halogen source was used during calcination. However, the spheres were almost completely destroyed. Our novel synthetic route can also be extended to other lanthanide fluorides (REF3, RE=Gd, Lu), which may open a facile way to fabricate novel porous nanostructures.  相似文献   

7.
In recent years, there has been a rapid expansion in the use of radio nuclides for therapeutic purposes. Thulium–167 is an important radionuclide (T 1/2 = 9.25 d) due to it could be used for tumor and bone studies in nuclear medicine. 167Tm complexed with hydroxy ethylene diamine tetra-acetic acid (HEDTA) could be used with the aim of bone imaging. 167Tm emits a prominent γ ray of 208 keV energy and low energy electrons. This study describes calculations on the excitation functions of 165Ho(α,2n)167Tm, 167Er(p,n)167Tm, natEr(d,xn)167Tm and natEr(p,xn)167Tm reactions by ALICE/ASH (hybrid and GDH models) and TALYS-1.0 codes. In addition, calculated data by codes were compared to experimental data that earlier were published and TENDL-2010 database. Moreover, optimal thickness of the targets and physical yield were obtained by SRIM (stopping and range of ions in matter) code for each reaction. According to the results, the 167Er(p,n)167Tm and 165Ho(α,2n)167Tm reactions are suggested as the best method to produce 167Tm owing to minimum impurities. The TALYS-1.0 code, predict the maximum cross-section of about 382 mb at 11 MeV and 849 mb at 26 MeV for 167Er(p,n)167Tm and 165Ho(α,2n)167Tm reactions, respectively. Finally, deposition of natEr2O3 on Cu substrate was carried out via the sedimentation method. The 516 mg of erbium(III)oxide with 103.2 mg of ethyl cellulose and 8 mL of acetone were used to prepare a natEr2O3 layer of 11.69 cm2. 167Tm was produced via the natEr(p,n)167Tm nuclear process at 20 μA current and 15 → 7 MeV protons beam (1 h). Yield of about 3.2 MBq 167Tm per μA h were experimentally obtained.  相似文献   

8.
Upconverting phosphor fine particles (Gd2O3:Yb,Er and Gd2O2S:Yb,Er) have been prepared, using an emulsion liquid membrane (ELM, water-in-oil-in-water (W/O/W) emulsion) system. The composite Gd-Yb-Er oxalate particles obtained in the ELM system were mainly 20-60 nm in size, together with a smaller amount of submicrometer-sized spherical particles. Nanometer-sized Gd2O3:Yb,Er and Gd2O2S:Yb,Er particles were obtained by calcination in air and in sulfur atmosphere, respectively, of the precursor oxalate particles prepared in the ELM system. Upconversion emissions (red and green) were obtained from the Gd2O3:Yb,Er and Gd2O2S:Yb,Er particles prepared in the ELM system under infrared excitation (lambdaex=980 nm) via a two-photon process. Upconversion phosphor fine particles, about 50 nm in diameter, may be applied to the luminescent reporter material for the detection of the targeted analyte in immunoassays or DNA assays.  相似文献   

9.
A natural cadmium foil was irradiated by 42 MeV α-particles to produce 113,117mSn, 111,113m,114mIn simultaneously in the target matrix. After the complete decay of short lived radionuclides, long-lived NCA products were separated sequentially from the bulk cadmium by liquid–liquid extraction using di-(2-ethylhexyl)phosphoric acid (HDEHP) dissolved in cyclohexane as organic phase and HCl as aqueous phase. At the optimum condition, 10?2 M HCl and 5 % HDEHP, NCA In along with NCA Sn radionuclides (75 %) were separated from the bulk Cd resulting to high separation factors of 2.7 × 104 (D In/D Cd) and 500 (D Sn/D Cd), respectively. The NCA In was stripped back completely to the aqueous phase by 6 M HCl leaving NCA Sn in the HDEHP phase with a separation factor (D Sn/D In) of 3.94 × 106.  相似文献   

10.
The nanocrystals (NCs) of tetragonal barium yttrium fluoride (BaYF(5)) doped 1 mol% Ln(3+) (Ln=Er, Tm, Ho) and 20 mol% Yb(3+) with different morphologies and sizes have been successfully synthesized through a facile hydrothermal method. The influences of pH values of the initial solution and fluorine sources on the final structure and morphology of the products have been well investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) were used to characterize the size, structure and morphology of these samples prepared at different conditions. And it is found that BaYF(5):Yb/Ln NCs prepared at pH value of 10 using NaBF(4) as F(-) source have a uniform spherical morphology with average diameter of 25 nm. Additionally, the up-conversion (UC) properties of Yb/Er, Yb/Tm, and Yb/Ho doped BaYF(5) nanoparticles were also discussed. Under 980 nm laser excitation, the BaYF(5):Yb/Er, BaYF(5):Yb/Tm, and BaYF(5):Yb/Ho NCs exhibit green, whitish blue, and yellow green UC luminescence, respectively. The luminescence mechanisms for the doped lanthanide ions were thoroughly analyzed.  相似文献   

11.
The reduction specifics of REE orthovanadates LnVO4 (Ln = La, Nd, Sm, Dy, Ho, Er, Tm, Yb, and Lu) have been studied using the temperature-programmed reduction (TPR) method. Hydrogen and carbon monoxide were chosen as reducing agents. The reduction temperature is found to depend both on the REE and the reducing agent. REE orthovanadates are reduced in the range 1033–1153 K not forming phases that contain vanadium in intermediate oxidation states. In CO, the reduction temperature is found to be higher than in H2 for all orthovanadates. TPR data have been used to calculate the activation energies of reduction of REE orthovanadates using the Kissinger equation. The effective activation energies of reduction depend on the REE and the reducing agent and are in the range 41–147 kJ/mol.  相似文献   

12.
13.
Magnetic data are presented for LnMnO3 (Ln=Ho, Er, Tm, Yb, and Lu) having the hexagonal crystal structure of P63cm. DC magnetization measurements show that magnetic order is not clearly observed for Ln=Ho-Yb, while an antiferromagnetic transition of the Mn3+ moments is found at ∼90 K for LuMnO3, where the Lu3+ ion has no 4f localized moment. This is ascribed to both the paramagnetism of Ln3+ and the suppression of magnetization in the Mn3+ sublattices arising from strong antiferromagnetic interactions between Mn3+. Deviation from the Curie-Weiss law at low temperatures indicates the onset of antiferromagnetism. Some magnetization data of Ca-substituted compounds, Ln0.5Ca0.5MnO3, which have the different crystal structure of orthorhombic Pnma, are also discussed briefly.  相似文献   

14.
The title compounds were prepared from the elemental components in a lithium flux. Their crystal structure was determined for the ytterbium compound from single-crystal X-ray data. It is orthorhombic, Pmm2, a = 352.88(6) pm, b = 1 143.0(3) pm, c = 366.16(6) pm, Z = 1, R = 0.020 for 1 261 structure factors and 29 variable parameters. The structure may be viewed as an intergrowth of slabs consisting of the CeNiC2 and the ScC (NaCl type) structures. It thus contains C2 pairs with a C? C distance of 138(1) pm and isolated carbon atoms. Together with the nickel atoms the C2 pairs form one-dimensionally infinite building elements [Ni2C4]n. The fifth carbon atom is octahedrally coordinated by ytterbium atoms. Accordingly the compound may be rationalized to a first approximation with the formula (Yb3+)4[Ni2C48?]C4?. Yb4Ni2C5 shows Curie-Weiss behaviour with a magnetic moment of μexp = 4.44 μB per ytterbium atom in good agreement with the theoretical moment of μeff = 4.53 μB for Yb3+.  相似文献   

15.
Yttrium tungstate precursors with novel 3D hierarchical architectures assembled from nanosheet building blocks were successfully synthesized by a hydrothermal method with the assistance of sodium dodecyl benzenesulfonate (SDBS). After calcination, the precursors were easily converted to Y(2)(WO(4))(3) without an obvious change in morphology. The as-prepared precursors and Y(2)(WO(4))(3) were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra, respectively. The results reveal that the morphology and dimensions of the as-prepared precursors can be effectively tuned by altering the amounts of organic SDBS and the reaction time, and the possible formation mechanism was also proposed. Upon ultraviolet (UV) excitation, the emission of Y(2)(WO(4))(3):x mol% Eu(3+) microcrystals can be tuned from white to red, and the doping concentration of Eu(3+) has been optimized. Furthermore, the up-conversion (UC) luminescence properties as well as the emission mechanisms of Y(2)(WO(4))(3):Yb(3+)/Ln(3+) (Ln = Er, Tm, Ho) microcrystals were systematically investigated, which show green (Er(3+), (4)S(3/2), (2)H(11/2)→(4)I(15/2)), blue (Tm(3+), (1)G(4)→(3)H(6)) and yellow (Ho(3+), (5)S(2)→(5)I(8)) luminescence under 980 nm NIR excitation. Moreover, the doping concentration of the Yb(3+) has been optimized under a fixed concentration of Er(3+) for the UC emission of Y(2)(WO(4))(3):Yb(3+)/Er(3+).  相似文献   

16.
Er5(BO3)2F9 was synthesised under conditions of 3 GPa and 800 °C in a Walker‐type multianvil apparatus. The crystal structure was determined on the basis of single‐crystal X‐ray diffraction data, collected at room temperature. Er5(BO3)2F9 is isotypic to the recently synthesised Yb5(BO3)2F9 and crystallises in C2/c with the lattice parameters a = 2031.2(4) pm, b = 609.5(2) pm, c = 824.6(2) pm, and β = 100.29(3)°. The physical properties of RE5(BO3)2F9 (RE = Er, Yb) including high temperature behaviour and single crystal IR‐ / Raman spectroscopy were investigated.  相似文献   

17.
The title structures of KScS2 (potassium scandium sulfide), RbScS2 (rubidium scandium sulfide) and KLnS2 [Ln = Nd (potassium neodymium sufide), Sm (potassium samarium sulfide), Tb (potassium terbium sulfide), Dy (potassium dysprosium sulfide), Ho (potassium holmium sulfide), Er (potassium erbium sulfide), Tm (potassium thulium sulfide) and Yb (potassium ytterbium sulfide)] are either newly determined (KScS2, RbScS2 and KTbS2) or redetermined. All of them belong to the α‐NaFeO2 structure type in agreement with the ratio of the ionic radii r3+/r+. KScS2, the member of this structural family with the smallest trivalent cation, is an extreme representative of these structures with rare earth trivalent cations. The title structures are compared with isostructural alkali rare earth sulfides in plots showing the dependence of several relevant parameters on the trivalent cation crystal radius; the parameters thus compared are c, a and c/a, the thicknesses of the S—S layers which contain the respective constituent cations, the sulfur fractional coordinates z(S2−) and the bond‐valence sums.  相似文献   

18.
The novel compounds of the MIIIU2O7.5 type (with MIII being yttrium or lanthanides from terbium to lutetium) have been prepared via hydrothermal synthesis from hydrated uranium(VI) oxide and aqueous solutions of M(III) nitrates at 200°C. Composition and structure of the products have been studied by means of elemental analysis, high-temperature X-ray diffraction, and IR spectroscopy; the products thermal stability has been estimated.  相似文献   

19.
20.
We report efficient white upconversion luminescence in Yb(3+)-, Er(3+)- and Tm(3+)-doped monophasic and biphasic Y(2)BaZnO(5) phosphors under 977 nm near-infrared excitation and at low excitation power densities (down to ~25 mW mm(-2)).  相似文献   

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