Phase and Rietveld Refinement of Pyrochlore Gd_2Zr_2O_7 Used for Immobilization of Pu(Ⅳ)

The phase of pyrochlore Gd2Zr2O7 used for immobilization of Pu(Ⅳ) was investigated, tetravalent cerium was used as the simulacrum for plutonium with tetravalence, and the compounds in the system Gd2Zr2-x Ce x O7(0.0 x 2.0) were synthesized via a high temperature solid reaction method with Gd2O3 and ZrO2 powders being used as the starting materials. Based on the collected XRD data of the gained samples, the phase and microstructural change of compounds were calculated by means of rietveld structural refinement method. The experimental results indicated that the phases of compounds were changed from pyrochlore to fluorite-type phase with the increasing x. The linear relation between a and x was discovered in the range of fluorite-type phase, which accorded with a = 0.52748 + 0.00825 x(0.2 x 2.0), while V = 0.14668 + 0.00711 x(0.2 x 2.0) was also achieved.     

Hydrothermal Synthesis and Characterization of a Novel Organic Inorganic Hybrid Compound [Co（dien）2]（dienH3）（H3O）7[P2Mo5O23]2·14H2O

A new compound,[Co（dien）2]（dienH3）（H3O）7[P2Mo5O23]2·14H2O, has been hydrothermallly synthesized by using Na2MoO4,CoCl2, H3PO4 and dien, and structurally characterized by elemental analysis, X-ray powder diffraction analysis, SEM, IR and TG analysis. The results show that the compound is composed of a polyanion [P2Mo5O23]2^12, complex [Co（dien）2]^2＋ cation, protonated [dienH3]^3＋ , and forteen crystallization water molecule.     

Gd2Zr2O7烧绿石的高温高压快速合成

为了研究Gd2Zr2O7烧绿石的合成条件,以Gd2O3,ZrO2混合粉体为原料,在1773K的温度、3GPa和5．2GPa的压力及10-30min的保温保压时间内,进行了高温高压实验。借助于XRD,SEM,IR等分析,对合成样品结构、形貌等进行表征,结果表明：在1773K的高温、5．2GPa的高压和10min的保温保压条件下可合成单一物相的Gd2Zr2O3立方烧绿石。为固化锕系核素的陶瓷基材合成及其固化体的制备提供了一种快速高效的方法。     

Leaching Stability of Simulated Waste Forms for Immobilizing An3＋ by Gd2Zr2O7 with Nd3＋

In order to investigate the anti-leaching capability of pyrochlore Gd2Zr2O7 immobilized An3+, trivalent neodymium was used as the simulacrums for radioactive wastes with trivalence, Gd2-xNdxZr2O7(0.0x 2.0) series samples were successfully synthesized by high temperature solid reaction and using Gd2O3, Zr O2 powders as starting materials. The experiments of long-term chemical stability were conducted in synthetic seawater at 40 and 70 ℃. The XRD diffractive data and extraction ratio of as-received samples were collected with the help of X-ray diffraction(XRD) instrument and inductively coupled plasma mass spectrometry(ICPMass). The results indicate that the phases of as-received compounds keep the single phase of pyrochlore. The extraction ratio of Gd3+, Zr4+ and Nd3+ in waste forms is increasing with the increase of immersion time in synthetic seawater. The extraction ratio of waste forms at 70 ℃ is higher than at 40 ℃. The highest extraction ratio of Gd3+, Zr4+ and Nd3+ after 42 days is near 0.025 8, 0.003 8 and 0.045 2 μg·m L-1, respectively.     

稀土Y2O3和Gd2O3共掺杂对La2 (Zr0.7Ce0.3)2O7陶瓷相结构及热膨胀系数的影响

采用固相合成法制备了(La1-2xYxGdx)2(Zr0.7Ce0.3)2O7(x=0,0.30,0.35,0.40,0.45,0.50)体系陶瓷材料.分别利用XRD、扫描电子显微镜和高温热膨胀仪对陶瓷材料的相组成、微观形貌及热膨胀系数进行测试.结果表明.掺杂量x=0时为立方烧绿石结构,x≥0.30时为立方萤1石结构;晶粒发育良好,晶界清晰;Y2O3和Gd2O3的掺杂可以有效的提高La2 (Zr0.7 Ce0.3)2O7的热膨胀系数.     

(Sm_(1-x)Er_x)_2Zr_2O_7粉体的制备及表征

采用溶胶凝胶法制备了(Sm1-xErx)2Zr2O7纳米粉体,采用XRD和FT-IR技术分析了粉体的相组成,用SEM和EDS分析了粉体的显微形貌和元素组成.结果表明,采用溶胶凝胶法成功地制备了纯净的具有焦绿石结构的(Sm1-x Erx)2Zr2O7纳米粉体,其颗粒尺寸为30~200 nm,各元素摩尔比与化学式一致.     

Conductivity of (Zr1-xMx)O2 Ceramic

In the ZrO_2-based ceramic systems doped with different oxides (Y_(2)O_3, MgO and Al_(2)O_3), the behaviors of electronic and ionic conductivity have been investigated by the quantum chemical SCF-X_α-SW method. The results of the electronic energy spectra and local state density of atoms show that, for the ZrO_2 system doped with Al_2O_3, the energy gap near the Fermi energy level becomes smaller, which implies that the electronic conductivity increases. Since the binding energy between Al and O atoms is increased, the energy for oxygen vacancy migrating is enhanced and the ionic conductivity decreases. In the M_xO_y-doped ZrO_2 systems, due to the doping effect of Al_2O_3, MgO and Y_2O_3, the ionic conductivity increases successively, and the electronic conductivity decreases successively. The cal- culation results are in agreement with that of references and experience.     

镧掺杂对Sm2Zr2O7介电和荧光性能的影响

采用溶胶凝胶和固相烧结法成功制备了纯净的具有焦绿石结构的（Sm1-xLax）2Zr2O7固溶体,该类材料组织结构致密、晶界清晰、无其他相或未反应物存在．大半径La^3＋的引入使ZrO6八面体体积增大,从而其介电常数逐渐增大;La的掺杂使其晶格有序度增大,从而使其荧光活性逐渐增强．     

(Gd2O3)x（ZrO2）1-x（x=0.05-0.15）电解质材料的电导及其分子动力学模拟

为了探讨作为固体氧化物燃料电池电解质材料的可行性,采用交流阻抗谱研究了(Gd2O3)x(ZrO2)1-x(x=0.05-0.15)固体电解质材料的晶粒电导率,并通过分子动力学方法模拟了Gd2O3掺杂ZrO2固体电解质材料的动力学行为,计算并分析了温度和Gd2O3掺杂量对体系离子传导性能的影响.实验和模拟结果均表明,升高温度能明显增强离子电导性能.当Gd2O3掺杂量为8 mol%时,材料的电导性能取得最优值.     

Microstructure refinement and magnetic properties enhancement of nanocrystalline Nd_(12.3)Fe_(81.7)B_(6.0) ribbons by addition of Zr

Effects of Zr addition and annealing treatment on the formation, microstructure and magnetic properties of Nd12.3Fe81.7?xZrxB6.0 (x=0―3.0) ribbons melt-spun and annealed have been systematically investigated by means of vibrating sample magnetometer (VSM), differential scanning calorimeter (DSC), X-ray diffraction (XRD), and high resolution scanning electron microscopy (HRSEM). Phase analysis reveals that Nd2Fe14B is single-phase material. It has been found that the intrinsic coercivity Hci of the optimally...     

H_2O_2-N_2OH-Sn(Ⅱ)/Sn( Ⅳ)体系电化学振荡行为

选择Ｈ２Ｏ２浓度为０．３８～１． １８ ｍｏｌ／Ｌ,考察各种因素对Ｐｔ电极上Ｈ２Ｏ２。在控电流条件下电势振荡行为的影响,在此基础上,构造了一个新的电化学振荡器即 Ｈ２Ｏ２－ ＮａＯＨ－ Ｓｎ（Ⅱ）／Ｓｎ（Ⅳ）电化学振荡体系,进一步得到该电化学振荡体系的一些规律。     

Eu~(3+)掺杂Gd_(9.33)(SiO_4)_6O_2微晶玻璃的制备及发光性能研究

采用高温熔融法制备Si O2-Na F-Na2O-Gd2O3-Eu2O3系基质玻璃,热处理后获得微晶玻璃.通过差热分析(DTA)、X射线衍射(XRD)、电子扫描电镜(SEM)和荧光光谱等对样品进行分析.XRD结果表明:基质玻璃经700、750℃热处理2~4 h获得含Gd9.33(Si O4)6O2的微晶玻璃.晶粒尺寸随热处理温度的升高和时间的延长而增大.荧光光谱研究结果表明:与基质玻璃相比,微晶玻璃的激发强度和发射强度明显增强,微晶玻璃中电荷迁移带发生偏移,5D0—7F1跃迁的发射峰出现劈裂,5D0—7F2与5D0—7F1跃迁强度比值减小,表明Eu3+进入Gd9.33(Si O4)6O2晶格中;微晶玻璃中5D0—7FJ特征发射峰和激发峰强度随热处理温度的升高和热处理时间的延长而增强.