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1.
Ag1 − x Mg1 − x R1 + x (MoO4)3 NASICON-like solid solutions, where R = Al or Sc and 0 ≤ x ≤ 0.5, were prepared; their crystal lattice parameters and thermal stabilities were determined. Silver-ion conductivity was measured, and conductivity activation energy values were calculated for various temperature ranges. Above 400°C, Ag1 − x Mg1 − x R1 + x (MoO4)3 phases have ionic conductivities comparable to the conductivities of sodium-ion and lithium-ion NASICON-like conductors. The conductivity increases as the tervalent cation radius increases or the amount of mobile silver ions increases.  相似文献   

2.
The possibility of preparing two series of solid solutions in the system Ba3 − x Sr x Er(BO3)3 (0 ≤ x ≤ 3.0), crystallizing in different structural types, was examined. Samples of the phases of variable composition were synthesized by the method of solid-phase reactions, and their X-ray phase analysis was done. The X-ray diffraction characteristics of the phases synthesized were determined. Original Russian Text ? T.N. Khamaganova, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 7, pp. 1210–1212.  相似文献   

3.
The synthesis conditions for variable-composition phase Na1−x Co1−x Fe1+x (MoO4)3, 0 ≤ x ≤ 0.4, crystallizing in the nasicon structure type (R $ \bar 3 $ \bar 3 c) were examined. For this phase, the crystallographic parameters were calculated, vibrational spectra were interpreted, and temperature dependence of electrical conductivity, dielectric constant, and dielectric loss tangent were examined.  相似文献   

4.
Sol–gel auto-combustion method is adopted to prepare solid solutions of nano-crystalline spinel oxides, (Ni1 − x Zn x )Fe2O4 (0 ≤ x ≤ 1).The phases are characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy, selected area electron diffraction, and Brunauer–Emmett–Teller surface area. The cubic lattice parameters, calculated by Rietveld refinement of XRD data by taking in to account the cationic distribution and affinity of Zn ions to tetrahedral sites, show almost Vegard’s law behavior. Galvanostatic cycling of the heat-treated electrodes of various compositions are carried in the voltage range 0.005–3 V vs. Li at 50 mAg−1 up to 50 cycles. Phases with high Zn content x ≥ 0.6 showed initial two-phase Li-intercalation in to the structure. Second-cycle discharge capacities above 1,000 mAh g−1 are observed for all x. However, drastic capacity fading occurs in all cases up to 10–15 cycles. The capacity fading between 10 and 50 cycles is found to be greater than 52% for x ≤ 0.4 and for x = 0.8. For x = 0.6 and x = 1, the respective values are 40% and 18% and a capacity of 570 and 835 mAh g−1 is retained after 50 cycles. Cyclic voltammetry and ex situ transmission electron microscopy data elucidate the Li-cycling mechanism involving conversion reaction and Li–Zn alloying–dealloying reactions.  相似文献   

5.
Transport numbers of oxygen ions, , in methacomposites (1 − x)MeWO4 · xWO3, where Me = Sr and Ba and x = 0−0.55, are determined in the temperature interval 600 to 900°C by a method of the emf of an oxygen-air galvanic cell. It is demonstrated that the region of small contents of the additive (x ≤ 0.2) is predominantly characterized by oxygen-ion conduction ( = 1), which gives way to electronic conduction (t e = 1) at x > 0.35. It is confirmed once again that subeutectic compositions (1 − x)MeWO4 · xWO3 where Me = Sr and Ba and x = 0−0.2 belong in the class of ion-conducting methacomposites. The threshold of percolation of electronic conduction (t e ≥ 0.5, < 0.5) occurs at x t ≥ 0.3. Dependences of the transport numbers of the oxygen ions on the volume ratio between components in both composites resemble one another; specifically, the threshold composition contains nearly 20 vol % of WO3. The dramatic amplification (by 1–1.5 orders of magnitude) of the ionic conductivity in the methacomposites occurs at small contents of tungstic oxide (x ≤ 0.01). A chemical transport removal of excess tungstic oxide, which is segregated in the form of the surface compound MeW-s, from the surface of the MeWO4 grains destroys MeW-s, leading to a 10–15-fold drop of the ionic conductance. At x ≥ 0.05, the oxygen-ion conductance in the methacomposites is practically independent of their composition. A model for the formation and architecture of the methacomposites is qualitatively modified. The modified model takes into account doubled surface activity and mobility of the MeW-s phase with respect to MeWO4 and WO3. Original Russian Text ? N.N. Pestereva, A.Yu. Zhukova, A. Ya. Neiman, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 11, pp. 1379–1386.  相似文献   

6.
The electrical resistivity and Hall factor in n-CdAs2, p-ZnAs2, and n-Cd x Zn1 − x As2 were measured at hydrostatic pressures up to 9 GPa and quasi-hydrostatic pressures up to 50 GPa at room temperature. For n-CdAs2, a phase transition was discovered at p = 5.5 GPa; for p-ZnAs2, two phase transitions were discovered: one at P = 10–15 GPa and the other at p = 35–40 GPa. No anomalies were found on ρ(p) and R(p) curves for Cd x Zn1 − x As2 when p ≤ 9 GPa. Original Russian Text ? A.Yu. Mollaev, I.K. Kamilov, R.K. Arslanov, L.A. Saipulaeva, R.G. Dzhamamedov, S.F. Marenkin, A.N. Babushkin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 1, pp. 122–125.  相似文献   

7.
The rare earth-transition metal-indides RE 4IrIn (RE = Gd–Er) and the solid solutions RE 4 TIn1–x Mg x (RE = Y, Gd; T = Rh, Ir) were prepared by arc-melting of the elements and subsequent annealing. The rare earth sesquioxides were used as oxygen source for the suboxides RE 4IrInO0.25 (RE = Gd, Er). Single crystals of the indides were grown via slowly cooling of the samples and they were investigated via X-ray powder diffraction and single crystal diffractometer data: Gd4RhIn type, F [`4]\bar 4 3m, a = 1372.3(6) pm for Gd4IrIn, a = 1365.3(6) pm for Tb4IrIn, a = 1356.7(4) pm for Dy4IrIn, a = 1353.9(4) pm for Ho4IrIn, a = 1344.1(4) pm for Er4IrIn, a = 1370.3(5) pm for Y4RhIn0.54Mg0.46, a = 1375.6(5) pm for Gd4IrIn0.55Mg0.45, a = 1373.0(3) pm for Gd4IrInO0.25, and a = 1345.1(4) pm for Er4IrInO0.25. The rhodium and iridium atoms have a trigonal prismatic rare earth coordination. Condensation of the RhRE 6 and IrRE 6 prisms leads to three-dimensional networks which leave voids that are filled by regular In4 or mixed In4–x Mg x tetrahedra. The indium (magnesium) atoms have twelve nearest neighbors (3In(Mg) + 9RE) in icosahedral coordination. The rare earth atoms build up a three-dimensional, adamantane-like network of condensed, edge and face-sharing octahedra. For Gd4IrInO0.25 and Er4IrInO0.25 the RE16 octahedra are filled with oxygen. The crystal chemical peculiarities of these rare earth rich compounds are discussed.  相似文献   

8.
The rare earth-transition metal-indides RE 4IrIn (RE = Gd–Er) and the solid solutions RE 4 TIn1–x Mg x (RE = Y, Gd; T = Rh, Ir) were prepared by arc-melting of the elements and subsequent annealing. The rare earth sesquioxides were used as oxygen source for the suboxides RE 4IrInO0.25 (RE = Gd, Er). Single crystals of the indides were grown via slowly cooling of the samples and they were investigated via X-ray powder diffraction and single crystal diffractometer data: Gd4RhIn type, F 3m, a = 1372.3(6) pm for Gd4IrIn, a = 1365.3(6) pm for Tb4IrIn, a = 1356.7(4) pm for Dy4IrIn, a = 1353.9(4) pm for Ho4IrIn, a = 1344.1(4) pm for Er4IrIn, a = 1370.3(5) pm for Y4RhIn0.54Mg0.46, a = 1375.6(5) pm for Gd4IrIn0.55Mg0.45, a = 1373.0(3) pm for Gd4IrInO0.25, and a = 1345.1(4) pm for Er4IrInO0.25. The rhodium and iridium atoms have a trigonal prismatic rare earth coordination. Condensation of the RhRE 6 and IrRE 6 prisms leads to three-dimensional networks which leave voids that are filled by regular In4 or mixed In4–x Mg x tetrahedra. The indium (magnesium) atoms have twelve nearest neighbors (3In(Mg) + 9RE) in icosahedral coordination. The rare earth atoms build up a three-dimensional, adamantane-like network of condensed, edge and face-sharing octahedra. For Gd4IrInO0.25 and Er4IrInO0.25 the RE16 octahedra are filled with oxygen. The crystal chemical peculiarities of these rare earth rich compounds are discussed. Correspondence: Rainer P?ttgen, Institut für Anorganische und Analytische Chemie, Westf?lische Wilhelms-Universit?t Münster, Germany.  相似文献   

9.
Phases of a variable composition in the Ba3−x Sr x Y(BO3)3, system (0 < x < 3) have been investigated for the first time using the solid-phase reactions method. The formation of two series of solid solutions crystallizing in different structural types have been established using X-ray diffraction (D-8 Advance diffractometer, CuK α radiation, graphite monochromator). Crystal characteristics of obtained phases have been determined. Original Russian Text ? T.N. Khamaganova, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 4, pp. 553–556.  相似文献   

10.
The phase compositions of theLaVO4-SrMoO4(1) and Sr2GeO4-SrMoO4 (2) binary systems, which bound the Sr2GeO4-LaVO4-SrMoO4 (3) ternary system, and the LaSr2(VO4)(GeO4)-Sr2GeO4+SrMoO4 section (4) of system 3 are studied at subsolidus temperatures. Systems 1 and 2 consist of a mixture of the initial compounds, and the La1 − x Sr2 + x (GeO4)(V1 − x Mo x O4) (where 0 ≤ x ≤ 0.4) region of substitutional solid solutions with a palmierite structure is formed in system 3. The unit cell parameters of the solid solutions are determined. The distribution of the lanthanum and strontium cations over two positions of the cationic sublattice is described. Original Russian Text ? V.D. Zhuravlev, V.G. Zubkov, A.P. Tyutyunnik, Yu.A. Velikodnyi, N.D. Koryakin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 1, pp. 135–137.  相似文献   

11.
We study the effect of Y3+ ↔ Ba2+ and Cu2+ ↔ Fe3+ substitutions on the structure, thermal expansion, electrical conductivity, and thermal e.m.f. of layered ferrocuprate YBaCuFeO5 + δ · YBa(Cu1−x Fe x )2O5 + δ solid solutions with 0.45≤x≤0.55 are formed. The unit cell parameters, thermal expansivity, and oxygen nonstoichiometry index of the YBaCuFeO5 +δ phase (δ) are almost independent of variations in the cationic composition of this phase. The electrical conductivity of layered yttrium barium ferrocuprate increases, whereas the activation energy of conductivity decreases in response to Ba2+ → Y3+ and Cu2+ → Fe3+ substitutions (with increasing copper(III) proportion in samples). The thermal e.m.f. of ceramics decreases when composition deviates from the cationic stoichiometry (YBaCuFeO5 +δ). Original Russian Text ? A.I. Klyndyuk, E.A. Chizhova, V.M. Kononovich, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 10, pp. 1672–1676.  相似文献   

12.
Substitutional solid solutions (Cu1−y Zn y )2(OH)PO4·xH2O (0 ≤ y ⩽ 0.26, x = 0.1−0.2), (Cu1−y Co y )2(OH)PO4·xH2O (0 ≤ y ≤ 0.10, x = 0.1−0.2), and (Cu1−y Ni y )2(OH)PO4·xH2O (0 ≤ y ≤ 0.08, x = 0.1−0.2) were synthesized. The unit cell parameters of the resulting phosphates were determined, and their IR absorption spectra were measured. The reactants were H3PO4 and mixtures of hydrous carbonates of the appropriate metals. Thermolysis of the solid solutions was examined with (Cu1−y Co y )2(OH)PO4·xH2O (0 ≤ y ≤ 0.10, x = 0.1−0.2) as an example.  相似文献   

13.
采用喷雾干燥法结合后续的热处理,成功地制备了一系列新型的基于富锂层状固溶体Li_2MnO_3和Li[Ni_(0.8)Co_(0.15)Al_(0.05)]O_2结合的xLi_2MnO_3-(1-x)Li[Ni_(0.8)Co_(0.15)Al_(0.05)]O_2(0.5≤x≤0.8)材料,并对其晶体结构、表面形貌、元素价态以及电化学性能进行了一系列的研究。实验结果表明,随着x值的增大,材料的晶体结构逐渐从层状的Li[Ni_(0.8)Co_(0.15)Al_(0.05)]O_2过渡到类Li_2MnO_3结构。对样品进行淬火处理对晶粒的微观晶体结构和元素价态产生复杂影响,这种变化使得淬火的样品表现出较好的电化学性能。其中x=0.6的样品淬火后表现出较好的电化学性能,100次循环后可逆容量可达209 mAh·g~(-1)。  相似文献   

14.
Complex salts [Ir(NH3)5Cl]x[Rh(NH3)5Cl]1−x MO4 (x = 0.5, 1; M = Mo, W) are synthesized and their thermal properties are studied. The crystal structures are determined for [Ir(NH3)5Cl]WO4 and [Ir(NH3)5Cl]MoO4. In the structures, the ions are linked by N-H...O hydrogen bonds, the shortest ones being 2.868(2)–3.422(2) ?. and 2.860(4)–3.434(3) ?. respectively. The thermal properties of the complex salts are studied in the hydrogen atmosphere and in hydrogen-helium mixtures. It is demonstrated that the final products are the mixtures of nanocrystalline powders of Ir and binary or ternary solid solutions with the hcp lattice.  相似文献   

15.
The ion and proton transfer numbers were measured by emf method in La1 − x Sr x Sc1 − y Mg y O3 − α (x = y = 0.01–0.20) system in reducing hydrogen-containing atmosphere in the range of temperatures from 630 to 920°C and pH2O from 0.61 to 2.65 kPa. Total ionic, proton, and oxygen conductivities of this system was measured as well. The electroconductivity measurements were carried out vs. pO2 (from air to 10−14 Pa).  相似文献   

16.
CeO2-based solid solutions with a fluorite structure are promising materials as electrolytes of medium-temperature electrochemical devices. This work presents the results of systematic studies of structural and electric properties and oxygen nonstoichiometry of the Ce0.8(Sm1 − x Ca x )0.2O2 − δ system in a wide range of concentrations of 0 < x < 1 performed in order to establish the causes affecting the system conductivity and its behavior in a reducing medium. It is found that a single-phase solid solution of the fluorite type is formed in the whole concentration range. Parameters of its lattice cells decrease linearly at an increase in the concentration of Ca2+. Conductivity in air grows when calcium is added due to a decrease in the grain boundary resistance. The maximum conductivity in air was obtained for the composition of Ce0.8(Sm0.8Ca0.2)0.2O2 − δ and is 13.71 × 10−3 S/cm at 873 K. Studies of the dependence of conductivity of the partial pressure of oxygen showed that electron conductivity is observed at a higher oxygen partial pressure at an increase in the temperature and calcium concentration. The critical partial pressure of oxygen ( pO2 * )\left( {p_{O_2 }^* } \right) for the compositions of Ce0.8(Sm1 − x Ca x )0.2O2 − δ with x = 0; 0.2, and 0.5 is 1.83 × 10−16, 1.73 × 10−13, and 3.63 × 10−13 atm at 1173 K, respectively, and 2.76 × 10−21, 5.05 × 10−18, and 1.31 × 10−18 atm at 1023 K.  相似文献   

17.
NASICON materials of composition Li1 + x Zr2 − x In x (PO4)3(x = 0–1) were synthesized. The phase constitution, particle size, and conductivity of these materials were studied as s function of synthesis temperature. High-temperature X-ray powder diffraction was used to study phase transitions in the materials synthesized. Low levels (x ≤ 0.1) partial substitution of indium for zirconium considerably increase the lithium ion conductivity and reduce the activation energy for conduction compared to the parent compound.  相似文献   

18.
Ionic, proton, and oxygen conductivities are measured as functions of air humidity (pH2O = 0.04−3.57 kPa) in the BaZr1 − x Y x O3 − α system (x = 0.02−0.15) over the temperature range 600–900°C. The important result is obtained that dissolved water vapor determines not only proton transport, but also the overwhelming part of oxygen transport in BaZr1 − x Y x O3 − α.  相似文献   

19.
Compounds of trigonal cluster chloroaqua complexes with cucurbit[8]uril were synthesized by slowly evaporating HCl solutions of chalcogenides heterometallic cubane cluster complexes of molybdenum and tungsten with cucurbit[8]uril in air; the complexes were characterized by X-ray diffraction analysis: (H3O)8[Mo3S4(H2O)2.5Cl6.5]2Cl(PdCl4)·(C48H48N32O16)· 29H2O (a = 13.3183(17) Å, b = 13.7104(18) Å, c = 18.225(3) Å; α = 80.263(3)°, β = 77. 958(3)°, γ = 87.149(4)°, V = 3207.4(7) Å3, space group P , Z = 1, ρ(calc) = 1.900 g/cm3), (H3O)4 [Mo3S4(H2O)3Cl6]2·(C48H48N32O16)3·68H2O (a = 21.413(6) Å, c = 49.832(10) Å; γ = 120°, V = 19788(8) Å3, space group R , Z = 3, ρ(calc) = 1.695 g/cm3), (H3O)6 [Mo3S4(H2O)3Cl6]2Cl2·(C48H48N32O16)·12H2O (a = 15.881(2) Å, b = 17.191(2) Å, c = 23.276(4) Å; β = 98.865(15)°, V = 6278.7(15) Å3, space group P21/c, Z = 2, ρ(calc) = 1.638 g/cm3), [W3S4(H2O)5Cl4]2·(C48H48N32O16)3·35H2O (a = 21.038(3) Å; α = 61.20(1)°, V = 6762.0(14) Å3, space group R , Z = 1, ρ(calc) = 1.582 g/cm3). The [Mo3S4(H2O)3Cl6]2− anion complex was isolated as three geometrical isomers.Original Russian Text Copyright © 2004 by E. V. Chubarova, D. G. Samsonenko, H. G. Platas, F. M. Dolgushin, A. V. Gerasimenko, M. N. Sokolov, Z. A. Starikova, M. Yu. Antipin, and V. P. Fedin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1049–1058, November–December, 2004.  相似文献   

20.
通过LiNO3与Mn(NO3)2的混合溶液与LiNi1/3Co1/3Mn1/3O2粉体共混干燥后在900℃热处理12 h制备了xLi2MnO3.(1-x)LiNi1/3Co1/3Mn1/3O2(x=0.1、0.2、0.3和0.4)固溶体。随着x的增加,固溶体的XRD峰强度减弱,峰形变宽,而在20°~30°间的结构特征峰(LiMn6)更加明显;尽管固溶体的外观形貌为团聚状,但组成其的单颗粒平均粒径随着x增大,由x=0.1时的250 nm增大到x=0.4时的350 nm。随着充放电截止电压的升高,固溶体的放电比容量增大;在2.5~4.6 V间充放电,当x=0.2时,充放电的极化最小,放电平台最高;不同倍率充放电循环21周后发现随着x的增大,容量保持率从91.2%增加大105.6%。研究结果表明,Li2MnO3可以改善LiNi1/3Co1/3Mn1/3O2材料的电化学性能。  相似文献   

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