非晶钛酸铋的晶化过程

利用差热分析、X射线衍射和透射电子显微镜等技术对溶胶-凝胶法合成的凝胶的晶化过程进行了分析，实验结果表明，Bi₄Ti₃O₁₂非晶凝胶晶化过程经历了四个过程：首先在433℃先形成了Bi₂O₃和TiO₂亚稳相，然后在488℃时TiO₂亚稳相与Bi₂O₃反应形成Bi，Ti复合氧化物亚稳相Bi₂T 关键词： 钛酸铋 铁电材料 溶胶凝胶 非晶 晶化过程     

Superconductivity and normal state resistivity of Ba0.6K0.4BiO3: an optical phonon approach

We discuss the nature of the pairing mechanism and the physical properties associated with the normal as well as the superconducting state of cubic perovskites Ba_0.6K_0.4BiO₃using the strong coupling theory. An interaction potential which includes the Coulomb, electron–optical phonon and electron–plasmon interactions is developed to elucidate the superconducting state. A model dielectric function is constructed with these interactions fulfilling thef-sum rule. The screening parameter (μ^* = 0.26) infers the poor screening of charge carriers. The electron–optical phonon strength (λ) estimated as 0.98 is consistent with an attractive electron–electron interaction and supports the moderate to strong coupling theory. The superconducting transition temperature of Ba_0.6K_0.4BiO₃is then estimated as 32 K. Ziman's formula of resistivity is employed to analyse and compare this with the temperature-dependent resistivity of a single crystal. The estimated contribution from the electron–optical phonon together with the residual resistivity clearly infers a difference when a comparison is made with experimental data. The subtracted data infer a quadratic temperature dependence in the temperature domain (30 ≤ T ≤ 200 K). The quadratic temperature dependence of ρ [ = ρ_exp − (ρ₀ + ρ_e–ph)] is understood in terms of 3D electron–electron inelastic scattering. The presence of these el–el and el–ph interactions allows a coherent interpretation of the physical properties. Analysis reveals that a moderate to strong coupling exists in the Ba_0.6K_0.4BiO₃system and the coupling of electrons with the high-energy optical phonons of the oxygen breathing mode will be a reason for superconductivity. The implications of the above analysis are discussed.     

[Bi2Cl10(H2-Norf)4(H2O)8](H-Norf是诺氟沙星)

CommentDuringinvestigationsonvariousmetalcomplexeswithH鄄Norf[1,2],complexationwithBiwasinvestigated.Fig.1showsthestructureofthefirstBi髥complexcontainingtheantibacterialdrugNorfloxacin○,[Bi2Cl10(H2鄄Norf)4(H2O)8].Thisisanioniccompoundcompris鄄ingfour[H2     

Reductive coupling of polyfunctionalized organobismuth and organolead arylating reagents in the synthesis of benzopyran derivatives

Benzopyran derivatives were synthesized in good yields by the reactions of tris[2-(chloromethyl)phenyl]bismuth diacetate and 2-(halomethyl)aryllead triacetates with phenols and naturally occurring 4-hydroxycoumarins in the presence of bases according to a three-step one-pot procedure. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2520–2529, November, 2005.     

Synthesis and thermal decomposition of lanthanide hexacyanochromate(iii) complexes,Ln[Cr(CN)6]·nH2O (Ln=La-Lu; n=3, 4)

New solid complex of nitrilotriacetic acid and bismuth trichloride was synthesized by a solid phase reaction of nitrilotriacetic acid and bismuth trichloride at room temperature. The composition of the sample is BiCl₃[N(CH₂COOH)₃]_2.5. The crystal structure of the complex belongs to triclinic system with the lattice parameters: α=0.7849 nm, β=0.9821 nm, χ=2.0021 nm, α=96.50°, β=98.76° and γ=90.49°. The far-infrared spectra show the bonding between the Bi ion and N atom of nitrilotriacetic acid. The thermal analysis also demonstrates the complex formation between the bismuth ion and nitrilotriacetic acid. The gaseous pyrolysis product and the final residue in the thermal decomposition process are determined to check the thermal decomposition reaction. This revised version was published online in August 2006 with corrections to the Cover Date.     

YPxV1—xO4（0≤x≤1）：Dy^3＋的合成及其光谱性质的研究

本文报道了不同组成的ＹＰｘＶ１－ｘＯ４（０≤ｘ≤１）：Ｄｙ＾３＋的合成和结构。ＹＰｘＶ１－ｘＯ４（０≤ｘ≤１）为四方晶系，晶胞参数随ｘ的增大呈线性减小。基质的Ｓｔｏｋｅｓ位移随ｘ的增大逐渐变大，而激发光谱峰值则向短波方向移动。在ＹＰｘＶ１－ｘＯ４：０．００６Ｄｙ＾３＋体系中，ｘ＞０．４时出现的基质发射是由ＰＯ＾３－４引起的。基质及Ｄｙ＾３＋的发光效率和Ｄｙ＾３＋的发光强度的黄蓝比均与ｘ有关。同时探     

溶胶—凝胶合成（Mg,Ca）O—SiO2：Eu^3＋,Bi^3＋发光体及其发光行为

以Ｍｇ（ＮＯ３）２，Ｃａ（ＮＯ３）２，Ｅｕ（ＮＯ３）３，Ｂｉ（ＮＯ３）３和Ｓｉ（ＯＣ２Ｈ５）４为反应物，采用溶胶－凝胶法，在比较低的温度，首次合成０．７０１ｍｏｌＭｇＯ－０．１７５ｍｏｌＣａＯ－１．２５ｍｏｌＳｉＯ２：０．０６ｍｏｌＥｕ＾３＋，０．００２ｍｏｌＢｉ＾３＋（加入Ｌｉ＾＋作为电荷补偿剂）发光体，得到了最佳合成条件，研究了由溶胶向凝胶转变和凝胶向发光晶体的转变过程，探讨了发光体在不同激光     

Einfache Trithio- und Perthiocarbonatokomplexe mit interessanter Koordinationschemie: [E(CS3)2]2− (E = Sn,Zn, Cd), [E(CS3)3]3− (E = As,Sb, Bi,Co), {Cu(CS3)−}∞ und [Zn(CS4)2]2−

Simple Trithio- and Perthiocarbonato Complexes with Interesting Bond Properties: [E(CS₃)₂]^2? (E = Sn, Zn, Cd), [E(CS₃)₃]^3? (E = As, Sb, Bi, Co), {Cu(CS₃)^?}_∞ and [Zn(CS₄)₂]^2? By reactions of potassium trithiocarbonate ( 1 ) with solutions of zinc(II)- acetylacetonate, cadmium(II)-chloride, tin(II)-chloride, arsenic(III)-sulfide (suspension), antimony(III)-chloride, bismuth(III)-chloride and copper(II)-chloride in dimethyl sulfoxide, as well as of trisodium hexanitrito cobaltate(III) in water, and the precipitation of the complexes with an aqueous solution of tetraphenylphosphonium chloride the compounds (PPh₄)₂[Zn(CS₃)₂] ( 2 ), (PPh₄)₂[Cd(CS₃)₂] ( 3 ), (PPh₄)₂[Sn(CS₃)₂] ( 4 ), (PPh₄)₃[As(CS₃)₃] ( 5 ), (PPh₄)₃[Sb(CS₃)₃] ( 6 ), (PPh₄)₃[Bi(CS₃)₃] ( 7 ), (PPh₄)₃[Co(CS₃)₃] ( 8 ) and (PPh₄)Cu(CS₃) ( 9 ) have been isolated. (PPh₄)₂[Zn(CS₄)₂] · CH₃NO₂ ( 10 ) has been prepared by heating a solution of 2 in nitromethane to 60--70°C in presence of air. The reaction of 1 in dimethyl sulfoxide with an aqueous tetraphenylphosphonium chloride solution in presence of oxygen leads to (PPh₄)₂[C₂S₆] ( 11 ). The compounds have been characterized by spectroscopical studies (IR, Raman, UV/Vis, ¹¹³Cd/⁵⁹Co-NMR), magnetic susceptibility measurements, powder diffractometry, elemental analyses and single crystal X-ray structure analysis ( 4 – 7 , 10 and 11 ). The difficult growing of single crystals has been reported in detail. For crystal data see Inhaltsübersicht.     

Formation of Bi-Sb, Bi-Sn, and Bi-Sb-Sn Nanoclusters in Silica Xerogel Matrices from Mixed-Metal Oxide Precursors

Homogeneous mixed-metal oxides of the general formula (Bi/E/Si)O _x , where E represents a dopant element (E=Sb, Sn, or Sb/Sn), can be prepared using typical sol-gel processing techniques. Reduction of the in-situ Bi(III) and E ions by hydrogen affords nanocomposites of Bi-Sb, Bi-Sn, or Bi-Sb-Sn widely dispersed throughout the silica xerogel matrix. The materials prepared have high Bi-E metal loading of 52–60 wt. % containing Bi-E alloy nanoclusters of 12–15 nm average diameter. These results demonstrate a convenient method for the production of practical quantities of nanostructured bismuth alloy ceramic composites at high metal content.