高纯氧化镥中痕量铁的富集及测定研究

采用吡咯二硫代氨基甲酸铵（APDC）沉淀富集高纯氧化镥中痕量的铁,再将沉淀溶于甲基异丁基酮（MIBK）溶液中,分离富集后的溶液用石墨原子吸收法直接测定.当盐酸酸度控制在0.4 mol/L,加2%APDC溶液2 mL,沉淀放置时间为15 min,选取石墨炉原子吸收光谱仪的灰化温度1100℃,原子化温度2300℃时,铁的测定效果最佳.铅、镍、铬、钴、铜等基体元素对铁的测定基本无干扰.该方法具有较好的精密度和准确度,相对标准偏差为4.5%,加标回收率在94.0%～108.0%之间.     

Synthesis,structure and luminescent properties of a new Vernier phase Lu7O6F9 doped by Eu^3＋ as potential scintillator with unique lath tube architecture

To explore novel nano-scintillator with a controllable architecture, pure and Eu3+ doped lutetium oxyfluoride(Lu7O6F9) powder were synthesized by combining mild hydrothermal method and solid state calcination approach. The products were all pure orthorhombic Vernier phase demonstrated by X-ray powder diffraction(XRD). The detailed crystal structure was also studied by Reitveld refinement. Lath-like microcrystals composed of nanoparticles with unique hollow tube of the products were supported by the images of scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Excited by X-ray with W as the target, the pure product showed intense broad emission with the peak at about 400 nm suitable for modern photoelectric multiplier tube(PMT), while the Eu3+ doped sample transferred the incident energy to Eu3+ ions and gave strong 5D0→7Fj(j=0, 1, 2 and 4) emission, which fitted for imaging and labeling measurements. From the luminescent properties, both pure and Eu3+-doped products are potential excellent scintillator for X-ray imaging and other high energy detectors, and the pure product is also a good host candidate for rare earth doping.     

Effect of oxygen on tuning the TiNx metal gate work function on LaLuO3

This paper presents experimental evidence on effective work function tuning due to the presence of oxygen at the TiNx/LaLuO₃ interface. Two complementary techniques, internal photoemission and X-ray photoelectron spectroscopy, show good agreement on the position of the metal gate Fermi level to conduction (2.79 ± 0.25 eV) and valence (2.65 ± 0.08 eV) band edge for TiNx/bulk LaLuO₃ gate stacks. The chemical shifts of Ti2p and N1s core levels and different degree in ionicity of TiNx metal gates correlate with the observed valence band offset shifts. The results have significance for setting the band edge work function and resulting low threshold voltage for ultimately scaled LaLuO₃-based p-metal oxide semiconductor field effect transistor devices.     

PMBP萃取色谱法分离钪和镧系元素及钇的研究

研究了 PMBP 以环己烷为稀释剂萃取钪和镥的机理,补充了有关 PMBP 萃取钪的数据.本体系中钪和镥的 pH_(1/2)分别为2.85和2.86.对 PMBP 萃取色谱法分离钪和镧系元素及钇的条件进行了选择.该方法可应用于离子型稀土矿中微量钪的分离和分析.     

Polymerization of 2,2′‐dimethyltrimethylene carbonate by lutetium complexes bearing amino‐phosphine ligands

A series of lutetium alkyl, amino, and guanidinato complexes based upon an amino‐phosphine ligand framework had been prepared. These complexes were applied to initiate ring‐opening polymerization of 2,2′‐dimethyltrimethylene carbonate (DTC). The type of the initiator significantly influenced the catalytic activity of these complexes in a trend as follows: alkyl ≈ guanidinate > amide, whereas the complexes with flexible backbone between P and N atoms within the ligand exhibited higher activity than those with rigid backbone. The isolated PDTC had bimodal‐mode molecular weight distribution. The molecular weights of each fraction increased linearly with the conversion, indicating that there might be two active species. This had been confirmed by analyses of oligomeric DTC living species and oligomer with NMR technique as the metal‐alkoxide and the four‐membered metallocyclic lactate. Kinetic investigation displayed that the polymerization rate was the first order with the monomer concentration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Ce~(3+):LiYF_4和Ce~(3+):LiLuF_4晶体生长与其紫外光谱特征

采用提拉法在CF4气氛中生长高质量掺Ce3+的LiYF4和LiLuF4晶体.测试了晶体的紫外光谱,并从配位场理论角度解释了Ce3+在2种氟化物晶体中紫外光谱特性的差异.结果表明:Ce3+在LiYF4晶体的吸收谱宽度比在LiLuF4晶体中更宽.Ce3+:LiYF4晶体的吸收峰和荧光峰的位置相对Ce3+:LiLuF4晶体的出现紫移.认为其主要原因是由于在LiYF4晶体中,Ce3+和相邻的F的距离更近,Ce3+的d电子与F之间的相互排斥作用更大.     

Infrared spectroscopy analyses of air-CH4 or air-CO gas flows interacting with polycrystalline CeO2, La2O3 and Lu2O3 oxides

A comparative study of reactivity between air-CH4 or air-CO gas flows and CeO2, La2O3 and Lu2O3 rare earth oxides was performed using Fourier transform infrared spectroscopy analyses of CO2 gas resulted from the conversion of CH4 or CO gases. Polycrystalline samples of CeO2, La2O3 and Lu2O3 were first prepared by specific precipitation methods followed by low temperature calcination process. In the case of Lu2O3 oxide, a new specific route was proposed. Crystallite dimensions were determined by X-ray diffraction and transmission electron microscopy analyses. Morphologies were characterized using scanning electron microscopy. Specific surface areas were determined from Brunauer-Emmett-Teller (BET) technique. Using infrared spectroscopy analyses, the conversion rates of CH4 or CO into CO2 were determined from the evolutions of CO2 vibrational band intensities, as a function of time and temperature. It was clearly established that, despite its low specific surface, the Lu2O3 oxide presented the highest capacity of conversion of CH4 or CO into CO2.     

Electrode Effect on Separation of Yb/Tm, Lu by an Electrolytic Reduction Process in Sulphate Medium

Electrode Effect on Separation of Yb/Tm, Lu by an Electrolytic Reduction Process in Sulphate Medium     

掺铈硅酸镥(Lu2SiO5:Ce)晶体的生长与闪烁性能

用Czochralsky方法和铱坩埚感应加热技术生长出了尺寸为φ35mm×40mm的掺铈硅酸镥(LSO:Ce)闪烁晶体.透射光谱表明,由于铈离子的掺入,使晶体的吸收边由纯LSO晶体的195nm红移至380nm.LSO:Ce晶体的紫外激发波长按强度递减的顺序依次为380、333、319和216nm,其光发射为带状谱,波长覆盖范围从390nm至560nm.X射线激发的发射谱具有典型的双峰特征,峰值波长为393nm和.426nm.这些特征与Ce3+离子基态能级4f1因自旋-轨道耦合而产生的两个分裂能级和Ce+离子在LSO晶体中占据两个不同的结晶学格位有关.