BaxCe0.8Y0.2O3-α固体电解质的氧离子导电性

Ba_xCe_0.8Y_0.2O_3-α(x=1.03，1，0.98) solid electrolyte samples show a single phase of orthorhombic perovskite of BaCeO₃. The oxide-ion conduction and transport number were detected in the temperature of 600～1000℃ by electrochemical oxygen permeation (oxygen pumping)， and compared with the results from the oxygen concentration cell. The relation between the ingredient of Ba and oxide-ion conduction was also researched. It was found that these electrolytes exhibited the mixed oxide-ionic and electronic hole conduction under the experimental temperature and oxygen gas. The oxide-ion transport numbers are 0.1～0.6， which are close to the results of the oxygen con-centration cell. They increase as the decrease of Ba content in the samples.     

o-ZrW1.6Mo0.4O8·H2O正交相的合成与表征

The precursor ZrW_1.6Mo_0.4O₇(OH)₂(H₂O)₂ was characterized by IR and XRD methods. δ′-ZrW_1.6Mo_0.4O₈ was prepared by careful controlling the annealing conditions from the precursor and was determined to have the formula as o-ZrW_1.6Mo_0.4O₈·H₂O by TG-DSC, IR, and XRD methods. The relation between o-ZrW_1.6Mo_0.4O₈·H₂O and o-ZrW_1.6Mo_0.4O₈ was discussed through variable temperature XRD patterns. Further more, the mechanism of the precursor dehydration was suggested.     

Fe3O4磁液的悬浮率测定及稳定性研究

The paper first reported the preparation of ultrafine Fe₃O₄ powder about 8～10nm by improved chemical pre-cipitation method， then turned it into magnetic fluid. The phase analysis， morphology， ultrafine powder size and magnetic property were measured by XRD， TEM and vibrating sample magnetometer(VSM)，respectively. In ad-dition， a new method ， by analyzed the suspending percentage of Fe₃O₄ powder， was introduced to study the effects of concentration， pH value， centrifugal rate and time on the stability of the magnetic fluid.     

CexPr1-xO2-δ复合氧化物的XRD和Raman表征

A series of Ce_xPr_1-xO_2-δ mixed oxides were synthesized by sol-gel method and characterized by Raman and XRD techniques. When x value was changed from 1.0 to 0.5, only a cubic phase CeO₂ was observed. The samples were very well crystallized on decreasing x from 0.50 to 0.99. For Ce_xPr_1-xO_2-δ samples 465 cm^-1 and 1 150 cm^-1 Raman peaks are attributed to the Raman active F_2g mode of CeO₂. The broad peak at about 570 cm^-1 in the region of 0.3 ≤x≤ 0.99 can be linked to lattice defects resulting in oxygen vacancies. The new band at about 195 cm^-1 may be attributed to the asymmetric vibration caused by the formation of oxygen vacancies. Calcination temperatures had great effect on the peak intensity for CeO₂ but less effect on Ce_0.8Pr_0.2O_2-δ in Raman spectra. It might be due to the transformation of the colors for the mixed oxides, the insertion of Pr atom into the ceria lattice could enhance the sintering resistance and thermal stability of the mixed oxides.     

球形Gd2O3∶Eu纳米发光材料的制备

Spherical nanometer Gd₂O₃∶Eu luminescent materials were prepared by homogeneous precipitation method, and the properties were studied also. TG, FTIR and XRD analysis showed that the precursor was carbonate, the cubic Gd₂O₃was obtained after calcination. TEM photographs indicated that the samples were spherical and well dispersed with nanometer and submicrometer size of 200～300 nm which is the nanoparticles’ aggregate. The mechanics of agglomerating growth is also discussed. ED photograph showed that the particle was crystalline. The PL analysis exhibited that CTB band of nanometer Gd₂O₃∶Eu was of 17 nm red shift to bulk materials, and the emission peak was broadened due to the surface and interface effect of nanocrystals.     

电镀烧结法制备Ti/SnO2-Sb2O4电极的研究

The Ti/SnO₂-Sb₂O₄ electrode has been prepared by the electroplate-sinter method. The effect of SbCl₃ adding amount and sintering temperature on its electrode lifetime and oxygen evolution potential were investigated by means of EDX, SEM and XRD analysis. The results indicated that the electrode appeared the best performance when the SbCl₃ adding amounts was 0.2g and the sintering temperature was 550℃. In optimized conditions Ti substrate was entirely covered by SnO₂-Sb₂O₄ and the combinations among them were tight. Due to the use of electroplate method, the electrical conductivity, the oxygen evolution potential and the electrode lifetime were increased, so the elec-tro-catalytic activity and the electrochemical stability of the prepared electrode were found to be superior.     

CeOHCO3和CeO2束状纳米结构的制备及表征

The cantaloupe-like particles of CeOHCO₃ were synthesized in aqueous solution by using cetyltrimethylammonium bromide (CTAB) as soft template. Then, the bunchiness rods of CeO₂ were obtained by calcining CeOHCO₃ at 450 ℃. The results of thermogravimetric/differential thermal analysis reveal that an endothermic reaction with decomposition is involved in the transformation process from CeOHCO₃ to CeO₂. By scanning electron microscopy and X-ray diffraction analysis, it is found that the orthorhombic phase CeOHCO₃ particles are constituted of short nanorods with diameters ranging from several tens nm to over 100 nm, and the cubic phase CeO₂ rods are composed of small particles with diameter ca. 15 nm. From the results of UV-Vis absorption and photoluminescence analysis, it is found that the CeO₂ possess abundant defects, and the band gaps of the CeO₂ and CeOHCO₃ are ca. 2.70 eV and 3.87 eV, respectively.     

锂离子电池正极材料LiMn2O4的合成与晶体结构（英）

Spinel LiMn₂O₄ powders were prepared using two-step synthesis method consisting of solid-state reaction method and citrate modified sol-gel method. The effects of the calcination temperature and the Li/Mn ratio of raw materials were studied on the physicochemical and electrochemical properties of the spinel LiMn₂O₄ powders, such as crystallinity, lattice constant and density. The title compound was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Polycrystalline LiMn₂O₄ powers calcined at 750 ℃ were found to be composed of very uniformly-sized microcrystal with an average particle size of 300 nm. The improvement in electrochemical properties was mainly attributed to the process of re-grinding by absolute alcohol.     

纳米Ce1-xLaxO2-δ的微波引诱燃烧合成及其性能表征

Nanometer Ce_1-xLa_xO_2-δ solid solutions were synthesized by microwave-induced combustion process us-ing cerium nitrate hexahydrate， lanthanum nitrate hexahydrate and urea as raw materials. The process took only six minutes to obtain La₂O₃-doped CeO₂ nanopowders. The nanopowders were characterized by XRD， Laser Raman spectrum ， UV-Vis spectroscopy，field-emission scanning electron micrograph(FE-SEM)and TEM. The results revealed that the grain size of Ce_1-xLa_xO_2-δ varied from 20 to 40 nm calculated by Scherer formula through the plane of (111)， that oxygen vacancy was produced in the crystal lattices and the concentration of oxygen vacancy was increased with La doping， therefore the covalence of Ce-O bond was strenthened， which results in more intensive UV-C(200～280 nm)absorption. It can be seen from SEM that the porous appearance was obtained. Grain size is no more than 40nm observed from TEM.     

球形La2O3∶Eu纳米晶的制备及其发光特性

The spheric La₂O₃∶Eu nanocrystals were prepared using NH₃·H₂O-NH₄HCO₃ mixture as precipitant. The material was characterized by FTIR, XRD and TEM techniques. The luminescence properties of Eu³⁺ in spheric La₂O₃ were measured by three dimension spectra, emission and excitation spectra. The results indicate that the La₂O₃∶Eu nanocrystals are in hexagonal phase by annealing at 800 ℃, the crystal size is about 30 nm. The maximum emission and excitation wavelength were determined by three dimensional spectroscopy to be at 591 nm and 394 nm, respectively. In emission spectrum the band at 591 nm and 612 nm are corresponding to ⁵D₀-⁷F₁ and ⁵D₀-⁷F₂ transition of Eu³⁺ ions. With increasing in annealing temperature the differences of intensity of the two transitions are increased. This phenomenon shows that the luminescence intensity of La₂O₃∶Eu nanocrystals can be tuned by changing annealing temperature.     

Li0.025Na0.975NbO3低温铁电相变及晶体结构

Li_(0.025)Na_(0.975)NbO_3 undergoes a ferroelectric-ferroelectric phase transition at 180K (on cooling) or 260 K (on heating). The structure determinations of both phases have been carried out by single crystal diffraction analysis. The ferroelectric room-temperature phase is orthorhombic, with space group Pc2_1b; the cell parameters are a=0.5508(3), b=1.5521(6), c=0.5568(2) nm. The structure is same with Li_(0.02)Na_(0.98)NbO_3. The ferroelectric low-temperature phase is also orthorhomhie, a=0.5497(7), b=0.7913(18), c=0.5565(10) nm, V=0.2421 nm, Z=4. There is disordernal position distribution of O(2) atomes in the low-temperature phase. Its “apparent space group” is P2/n2/n2/n. The relation of the ferroelectric properties to the low-temperature phase structure is discussed.     

新型笼状同多钒酸盐[Ni(1,10′-phen)3]2·[V2ⅣV8ⅤO26]的水热合成和晶体结构

尽管多金属氧酸盐(POMs)的研究已有180多年的历史, 但大量的POMs结构在最近几十年才被陆续解析出来[1～4].     

层状类钙钛矿结构新铌酸盐KSr2Nb3O10

A new niobate compound KSr₂Nb₃O₁₀ was synthesized for the first time. The chemical compositions, crystal structure, optical property, density and melting point of the new compound were characterized by EPMA, TEM, XRD, DTA and so on. KSr₂Nb₃O₁₀ crystallizes the orthorhombic system with unit cell parameters a=0.7816(1) nm, b=0.7764(2) nm, c=2.9995(2) nm, V=1.8114(4) nm³, and space group P2₁2₁2₁, Z=8. The structure may be described as treble perovskite sheets ［Sr₂Nb₃O₁₀］^- interleaved with K⁺. Further, it was found that KSr₂Nb₃O₁₀ has intercalation phenomenon. Na⁺, Li⁺, H⁺, NH⁺₄ could exchange the interlayer cations K⁺ of KSr₂Nb₃O₁₀, and n-hexylamine also could intercalate into the place between the layers of ［Sr₂Nb₃O₁₀］^-.     

新钽酸盐Ba3TiTa4O15的结构与介电性能

在BaO Ta2O5系统通过掺Ti4＋合成了新钽酸盐Ba3TiTa4O15,用粉晶XRD对其结构进行了分析,并测试了其烧结体的介电特性.结果表明:Ba3TiTa4O15在室温下属于填满型四方钨青铜结构,晶胞参数a=1.256 27(6)nm, c=0.395 86(4)nm; Ba3TiTa4O15在－35 ℃从铁电相转变为顺电相.     

Hydrothermal synthesis and thermal properties of a novel cubic ZrW1.80V0.20O7.90 solid solution

Tetragonal ZrW_1.80V_0.20O_6.90(OH)_2.00(H₂O)_2.00 hydrate was prepared using an acidic steam hydrothermal (ASH) method. Thermal dehydration followed by phase transformation of this precursor leads to successful synthesis of a novel W-site low-valent substituted cubic ZrW_1.80V_0.20O_7.90 solid solution, the mechanism of this process is studied in detail revealing the hydrate and a metastable orthorhombic phase of V′_Wsubstitution solid solution as important intermediate product. This material is found to possess thermal contraction and order-disorder phase transformation properties similar to that of the cubic ZrW₂O₈.     

纳米钙钛矿LaxSr1-xFe1-yCoyO3复合氧化物的制备和表征

用甘氨酸-硝酸盐燃烧合成法，制备La_xSr_1-xFe_1-yCo_yO₃复合氧化物的陶瓷粉末，对该钙钛矿型氧化物进行了XRD、IR、紫外漫反射光谱及循环伏安曲线分析。结果表明：该复合氧化物粉体平均晶粒为15.3～29.8 nm,为立方和正交晶系。该氧电极具有双功能催化特性，但不完全可逆。对水溶液染料进行光解实验，利用紫外-可见、人工神经网络光度法研究La_xSr_1-xFe_1-yCo_yO₃的催化性能。结果表明：CO²⁺的加入可使La_xSr_1-xFeO₃的光催化活性有所提高，B位离子(Fe³⁺，CO²⁺)改变与加入，使La_xSr_1-xFe_1-yCo_yO₃(x=0.7，0.3；y=0.3，0.9，1)光催化活性高于La_xSr_1-xFeO₃。同时，对5种染料进行紫外光解，在0.75 h，脱色率大于91%，并为动力学一级反应。     

簇合物(μ-SC6H5)(μ-P(SC6H5)2)Fe2(CO)6的合成和晶体结构

用Fe_3(CO)_(12)与亚磷酸三硫代苯酯P(SC_6H_5)_3反应得到标题化合物。P(SC_6H_5)_3以其裂解分子片SC_6H_5和P(SC_6H_5)_2配位。用X-ray衍射技术测定了该化合物的晶体结构, 晶体属正交晶系, 空间群为Pbca, a=1.7422(7), b=1.0634(6), c=2.898(12) nm; V=5.370 nm, z=8, D_c=1.579 g·cm~(-3)。由直接法和差值Fourier合成解出全部非氢原子坐标, 并用全矩阵最小二乘法修正, 最后偏离因子R=0.054, R_w=0.058, 分子结构中心的Fe_2SP折叠环沿S…P线或沿Fe—Fe键折叠的二面角(分别为76.1°和82°)比其它具有中心Fe_2S_2, Fe_2P_2和Fe_2SP折叠环的类似化合物中的相应值小, Fe—Fe键长为0.2572 nm, Fe—S(1)—Fe=68.6°, Fe—P—Fe=70.7°。     

Ba2CdMoO6及新化合物—Sr2CdMoO6晶体结构的研究

自从对Sr_2CaWO_6的相变和晶体结构研究以后,引起了我们对该类型化合物A_2~ⅡB~ⅡB~ⅥO_6的兴趣(A~Ⅱ=Ba~( 2),Sr~( 2);B~Ⅱ=Ca~( 2),Cd~( 2),Fe~( 2),Co~( 2),…;B~Ⅵ=W~( 6),Mo~( 6)),它们属于复杂的钙钛矿型结构,且具有一定的规律性。据文献[2]报导Ba_2CaWO_6属立方晶系,而文献[1]报导Sr_2CaWO_6低温相属正交晶系。在元素周期表中Mo和W同属于ⅥB族,它们的化学性质相似,二元素的离子半径也非常相近,Cd和Ca虽不同族,但离子半径很相近,化合价相同。为此,本文用Mo~( 6)代替W~( 6),Cd~( 2)代替Ca~( 2)来研究Ba_2CdMoO_6和Sr_2CdMoO_6的晶体结构。文献[3]对Ba_2CdMoO_6做了简单的报导,但Sr_2CdMoO_6则未见报导。     

新型微孔磷酸铝[C4N2H14]2+[H2Al3P3O14]2-的合成、结构及相转变

以3-甲氨基丙胺为结构导向剂,在水热条件下合成了1个具有三维开放骨架结构的微孔磷酸铝化合物[C4N2H14][H2Al3P3O14](1),并通过X射线单晶衍射确定了其结构,用粉末X射线衍射(PXRD)、热重(TG)、元素分析(ICP及CHN)和扫描电子显微镜(SEM)对其进行表征.结果表明,化合物1属正交晶系,Pbca空间群,晶胞参数a=1.59839(11)nm,b=0.99402(6)nm,c=1.82261(11)nm,V=2.8958(3)nm3.化合物1的无机骨架由铝氧多面体(AlO5/AlO6)和磷氧四面体(PO4)严格交替连接构筑而成,形成了在[010]方向上具有一维十元环孔道的三维阴离子开放骨架.每个P原子通过桥氧原子与相邻的4个Al原子相连,而Al原子除了通过桥氧原子与相邻的4个P原子相连之外,还通过羟基的桥氧原子与1个或2个Al原子相连,分别形成五配位和六配位的Al.化合物1在550℃空气或氧气气氛下灼烧5 h后转变为具有ATV分子筛结构的微孔磷酸铝分子筛AlPO4-25,且一直稳定到800℃.