排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
A new vanadate PbCo2V2O8 was obtained through the study of PbO-CoO-V2O5 ternary system. The crystal structure was determined by Rietveld method, indicating that PbCo2V2O8 has a tetragonal structure of space group I41cd with a spiral chain along the c-axis. Magnetic properties of the titled compound were investigated by means of susceptibility, magnetization, and heat capacity measurements. The results show that PbCo2V2O8 is a quasi-one-dimensional canted antiferromagnet with Neel temperature of ∼4 K, being consistent with its crystal structure. 相似文献
2.
Franco Varsano Francesca Decker Enrico Masetti 《Monatshefte für Chemie / Chemical Monthly》2001,132(1):83-95
Summary. Ce-V mixed oxide films have been deposited by RF sputtering with the aim of increasing the Li charge capacity of counter
electrodes in smart windows. Such mixed oxides have shown high transmittance and optical passivity in the visible region.
After electrode pre-conditioning by cyclic voltammetry, a good electrochemical reversibility in LiClO4– propylene carbonate electrolyte was observed, and large Li-charge capacity under galvanostatic charging (up to 50 mCċcm−2) has been measured. The electrode charge capacity decreased after prolonged insertion-deinsertion cycles, whereas the photoptic
transmittance remained about constant. After 800 cycles the Li-charge capacity decreased to 40 mCċcm−2. The Li diffusion coefficient inside the films measured by electrochemical impedance and by galvanostatic titration ranged
from 10−11 cm2ċs−1 to 10−13cm2ċs−1. We observed that the Li charge capacity of the film electrodes is a function of the film deposition conditions, because
it increased with the vanadium oxide concentration in the target and with the oxygen content in the sputtering atmosphere.
Received June 23, 2000. Accepted (revised) August 7, 2000 相似文献
3.
The infrared and Raman laser spectra of RbVOPO4 were recorded and briefly discussed with the aid of factor group analysis. Some comparisons with the spectra of related materials were also made. 相似文献
4.
A solid-state metathesis approach for the synthesis of hydrated MnV2O6·xH2O (x=2, 4) materials driven by mechanochemical activation energy has been demonstrated. The metathesis pathway of forming the desired product is confirmed by the presence of high lattice energy by-product such as NaCl. The structural, optical, and chemical properties of the synthesized materials are examined by powder X-ray diffraction, X-ray photoelectron spectroscopy, thermo gravimetric analysis, scanning electron microscopy, transmission electron microscopy, and diffused reflectance measurements in the UV–vis range. The valence state of Mn and V was determined to be +2 and +5, respectively, for the title compounds and the bandgap values determined showed these materials are likely to be semiconductors. 相似文献
5.
Anna V. Klassen Makoto Matsukura Osamu Nakamura Vladimir V. Kochurikhin Mikhail A. Ivanov Galina Yu. Orlova Akio Miyamoto Yasunori Furukawa 《Journal of Crystal Growth》2008,310(11):2895-2898
The applicability of the edge-defined film-fed growth (EFG) technique for YbxY(1−x)VO4 (x=0.05, 0.1 and 1) was approved by successful growth of crystals up to 80 mm in length as the thin plates. Low-angle grain boundaries and the crystal coloration as main defects were found. Optimal seed orientation was suggested on the strength of vanadate crystal plate morphology. Optical properties, chemical composition and the crystalline quality were investigated. 相似文献
6.
7.
《Journal of Coordination Chemistry》2012,65(9):1475-1483
Hydrothermal reactions have been exploited in the syntheses of two new metavanadates, {[Co(dpa)2]2V4O12}?·?H2O (1) and {[Ni(dpa)2]2V4O12}?·?H2O (2), which were characterized by X-ray diffraction, IR and thermogravimetric analysis. Crystal data: C40H38N12O13Co2V4 (1) monoclinic. P2(1), a?=?10.126(2), b?=?17.639(4), c?=?12.930(3) Å,?α?= 90°,?β?= 98.356(4)°,?γ?= 90°, Z?=?2; C40H38N12O13Ni2V4 (2) monoclinic. P2(1), a?=?10.1037(9), b?=?17.6680(14), c?=?12.8832(10) Å,?α?= 90°,?β?= 98.423(2)°,?γ?= 90°, Z?=?2. The two complexes are isomorphic and their structures consist of a [V4O12]4? cluster bound to two [M(dpa)2]2+ moieties through the terminal oxygen atoms in a trans-conformation; the [V4O12]4? cluster adopts a chair-like configuration. 相似文献
8.
Angela Šurca Vuk Boris Orel Goran Dražič 《Journal of Solid State Electrochemistry》2001,5(7-8):437-449
In this paper we generalize the IR spectroscopic properties of M3+VO4 (M=Fe, In) orthovanadate and Fe2V4O13 films. The films were prepared using the sol-gel synthesis route from M3+ nitrates and vanadium oxoisopropoxide. The vibrational bands in the IR absorbance spectra of the films are classified in
terms of terminal V-O stretching (1050–880 cm–1), bridging V-O...Fe and V...O...Fe stretching (880–550 cm–1), mixed V-O-V deformations and Fe-O stretching (<550 cm–1) modes. Ex situ IR spectra of films were measured after consecutive charging/discharging to various intercalation coefficients x and correlated to the current peaks in the cyclic voltammetry curves measured in 1 M LiClO4/propylene carbonate electrolyte. We classified the ex situ IR spectra of charged/discharged films according to their vibrational
band changes. The results reveal that, for small values of the intercalation coefficient, crystalline FeVO4, InVO4 and Fe2V4O13 films exhibit a simultaneous decrease in the intensity of all IR bands while the band frequencies remain unaffected. For
the higher intercalation levels, IR mode frequencies are shifted, signaling the presence of reduced vanadium. Further charging
leads to an amorphization of the film structure, which was established from the similarity of the IR spectra of charged films
with those of amorphous films prepared at lower annealing temperatures. The results confirm that ex situ IR spectroelectrochemical
measurement is an effective way to assess the structural changes in films with different levels of intercalation.
Electronic Publication 相似文献
9.
10.
The neutron diffraction patterns of Mg2FeV3O11-δ compound at various low temperatures have been investigated. No magnetic ordering was observed in the investigated temperature range down to 10K. These materials have been formed in the triclinic space group but there are specific differences in the positions of atoms as compared to previously determined from XRD method. The iron(III) ions are distributed non-statistically with magnesium(II) ions and this could be responsible for some differences in the structure of the above sample. The method of sample preparation, in particularly thermal annealing processes could be responsible for the differences. 相似文献