3-硝基-1,2,4-三唑-5-酮(NTO)铕配合物[Eu(NTO)3.(H2O)5].5H2O的制备和晶体结构

通过３－硝基－１，２，４－三唑－５－酮（ＮＴＯ）的锂盐水溶液与Ｅｕ_２Ｏ_３的稀硝酸溶液反应，制备了ＮＴＯ的铕配合物，用Ｘ射线分析法测定了它的单晶结构。所得晶体学参数如下：ａ＝１８．７２０（２）Ａ，ｂ＝６．５４８（３）Ａ，ｃ＝１９．３２３（３）Ａ，β＝９５．３３（１）°，Ｖ＝２３５８．３（５）Ａ￣３，Ｚ＝４，Ｄ_ｃ＝２．０２６ｇ／ｃｍ￣３，μ＝２７．６７８ｃｍ（－１），Ｆ（０００）＝１４３２，晶体属单斜晶系，空间群为Ｐ_（２４）／ｎ，最终偏离因子Ｒ为０．０２３３。     

Preparation and luminescence properties of europium complex with α-naphthylacetic acid incorporated in silica matrix by sol-gel method

Europium ternary complex of Eu (NNA)3 (NNA =α-naphthylacetic acid) was embedded in silica matrix at different ratios by sol-gel method. The luminescence properties of silica composites were studied by comparing them with those of corresponding pure complex by means of excitation, emission spectra and lifetimes. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix. The relative fluorescence intensity and fluorescence lifetimes increased simultaneously with the increase of Eu(NNA)3.     

Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

Transparent BaTiO₃:Eu³⁺ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO₃:Eu³⁺ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu³⁺ doped BaTiO₃.     

First principles computational studies of spontaneous reduction reaction of Eu(III) in eutectic LiCl‐KCl molten salt

Using first principles calculations, we study fundamental mechanism of spontaneous reduction reaction of Eu³⁺ to Eu²⁺ in eutectic LiCl‐KCl molten salt. We decouple the reaction Gibbs free energy into enthalpy and entropy contributions by using rigorous thermodynamic formalism. Key structural features of the solvation shell are characterized by the radial distribution function and the coordination number. Compared with Eu²⁺, the Eu³⁺ ion has a more rigid framework of the solvation shells, corroborating its stronger electrostatic interaction with neighboring ligands of Cl^? ions and a more favorable state on the aspect of enthalpy. Computations on vibrational frequency, however, pose significant contribution of vibrational entropy to the reaction Gibbs free energy for the reduction. Vibration frequency of Eu²⁺ is smaller than that of Eu³⁺, driving a more positive change of the entropy in the reduction reaction. Furthermore, an Eu²⁺ diffuses more quickly than an Eu³⁺ in the LiCl‐KCl molten salt with switching mechanism of ligand Cl^? ions in the solvation shell. Our results propose that the spontaneity of the reduction reaction is driven by the entropic contribution by overcoming the penalty of the reaction enthalpy.     

Photoelectric properties of thin Eu3+-doped TiO2 films sensitized by cis-RuL2(SCN)2·2H2O

Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O(L=cis-2,2'-bipyridine-4,4'-dicarboxlic acid) ruthenium complex were studied. The thin filmswere characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes toimproving the photoelectric properties. It is found that an optimal compositiondoped with 0.2 mol.% Eu3+ exhibits the highest photoelectric properties. I sc is 0.37 mA·cm-2 , which is 0.17mA·cm-2 bigger than that of un-doped films;Voc is 405 mV, which is 50 mV bigger than thatof un-doped films.     

用校正质谱法测量铕同位素丰度的研究

用确定化学纯度的151Eu、153Eu两种浓缩同位素配成9个混合样品，用来测量质谱计系统误差的校正系数，以校正用该仪器测出的矿样和试剂样中铕同位素丰度比，求出铕同位素丰度的绝对值分别是47．810（42）at．％151Eu和52．190（42）at．％153Eu。用该值和已知的铕的核素质量，计算得到铕的原子量为151．9644（9），被定为新的国际标准值。     

Separation of yttrium from europium using a hollow fiber-supported liquid membrane with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester as an extractant

The separation of Y(III) from Eu(III) using a hollow fiber-supported liquid membrane with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (EHPNA) as an extractant was studied. The effects of HCl and metal concentrations in the feed solution, the EHPNA concentration in the membrane, and the HCl concentration in the stripping solution on the initial fluxes of the two metals and the separation factor were investigated. The optimum conditions for selective recovery of Y(III) from an equimolar solution of Y(III) and Eu(III) chlorides (0.001?mol?L^?1 each) were as follows: HCl concentration in the feed solution, 0.1?mol?L^?1; EHPNA dimer concentration in the organic phase in the membrane, 0.1?mol?L^?1; and HCl concentration in the stripping solution, 4?mol?L^?1. Under these conditions, complete Y(III) extraction was achieved after 1 ks of operation, and the Y(III) purity in the stripping solution was 84%.     

Structural and emission properties of Eu3+‐doped alkaline earth zinc‐phosphate glasses for white LED applications

Quaternary alkaline earth zinc‐phosphate glasses in molar composition (40 ? x)ZnO – 35P₂O₅ – 20RO – 5TiO₂ – xEu₂O₃ (where x=1 and R=Mg, Ca, Sr, and Ba) were prepared by melt quenching technique. These glasses were studied with respect to their thermal, structural, and photoluminescent properties. The maximum value of the glass transition temperature (T_g) was observed for BaO network modifier mixed glass and minimum was observed for MgO network modifier glass. All the glasses were found to be amorphous in nature. The FT‐IR suggested the glasses to be in pyrophosphate structure, which matches with the theoretical estimation of O/P atomic ratio and the maximum depolymerization was observed for glass mixed with BaO network modifier. The intense emission peak was observed at 613 nm (⁵D₀→⁷F₂) under excitation of 392 nm, which matches well with excitation of commercial n‐UV LED chips. The highest emission intensity and quantum efficiency was observed for the glass mixed with BaO network modifier. Based on these results, another set of glass samples was prepared with molar composition (40 ? x)ZnO – 35P₂O₅ – 20BaO – 5TiO₂ – xEu₂O₃ (x=3, 5, 7, and 9) to investigate the optimized emission intensity in these glasses. The glasses exhibited crystalline features along with amorphous nature and a drastic variation in asymmetric ratio at higher concentration (7 and 9 mol%) of Eu₂O₃. The color of emission also shifted from red to reddish orange with increase in the concentration of Eu₂O₃. These glasses are potential candidates to use as a red photoluminsecent component in the field of solid‐state lighting devices.     

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。     

红外光谱研究铕改性Mo/HZSM-5催化剂的表面酸性

采用红外光谱方法考察了催化剂样品中的探针分子吡啶在程序升温脱附过程中的谱图变化,将红外光谱的特征峰强度与样品温度进行关联,并进行微分处理。从而得知铕增强了Ｍｏ／ＨＺＳＭ－ ５ 催化剂的Ｂ 酸强度,而对Ｌ 酸强度无影响。