共查询到20条相似文献,搜索用时 765 毫秒
1.
N. Imanaka 《Ionics》2003,9(1-2):36-40
New types of multivalent ion conducting solid electrolytes have been extensively developed and their applications for chemical
sensors were investigated. Among the trivalent ion conductors, the highest ion conductivity was realized with the (AlxZr1−x)4/(4−x)Nb(PO4)3 solid electrolyte and the value reaches the region between yttria stabilized zirconia (YSZ) and calcia stabilized zirconia
(CSZ) of the representative oxide anion conductors. The above described Al3+ ion conducting (AlxZr1−x)4/(4−x)Nb(PO4)3 solid electrolyte was combined with YSZ, with accompanying the Y2O3-KNO2 solid solution as an auxiliary electrode for nitrogen monoxide (NO) gas sensing. The sensor response was rapid and a reproducible
output was continuously observed obeying the Nernst theoretical relationship in a typical NO gas content region in exhaust
gases.
Paper presented at the 9th EuroConference on Ionics, Ixia, Rhodes, Greece, Sept. 15 – 21, 2002. 相似文献
2.
A. V. Ivanov Yu. E. Kalinin V. N. Nechaev A. V. Sitnikov 《Physics of the Solid State》2009,51(12):2474-2479
The concentration dependences of the electrical resistivity and complex permeability of [“(Co45Fe45Zr10)
x
(Al2O3)100 − x
”/“α-Si: H”]
n
multilayer structures and (Co45Fe45Zr10)
x
(Al2O3)100 − x
composites have been studied. It has been established that introduction of a semiconductor interlayer into the (Co45Fe45Zr10)
x
(Al2O3)100 − x
composites substantially decreases the electrical resistivity of [“(Co45Fe45Zr10)
x
(Al2O3)100 − x
”/“α-Si: H”]
n
multilayer structures. The concentration dependences of the real and imaginary parts of the complex permeability of the [“(Co45Fe45Zr10)
x
(Al2O3)100 − x
”/“α-Si: H”]
n
nanomultilayer structures substantially differ from those of the (Co45Fe45Zr10)
x
(Al2O3)100 − x
composites. The real part of the complex permeability of the [“(Co45Fe45Zr10)
x
(Al2O3)100 − x
”/“α-Si: H”]
n
nanomultilayer structures follows the curve with a minimum near the percolation threshold of the composite, and the imaginary
part smoothly decreases as the ferromagnetic phase concentration increases. The results obtained are explained by the increase
in the bifurcation temperature due to the conduction electrons of the semiconductor interlayer, which favor magnetic ordering
of ferromagnetic grains. 相似文献
3.
Thin sodium superionic conductor (Nasicon) coatings are deposited on rotating substrates by co-sputtering in the reactive
mode of a Zr-Si and a Na3PO4 target. The influence of the discharge current and of the target-to-substrate distance is investigated owing to the targeted
Na3Zr2Si2PO12 stoichiometry. A thermo-structural analysis shows that the amorphous as-deposited coating of convenient composition crystallises
around 700 °C in the monoclinic structure. Electrical measurements performed at room temperature after various annealing treatments
indicate a ionic conductivity of about 2·10−3 S·cm−1, consistent with that of bulk Nasicon.
Paper presented at the Patras Conference on Solid State Ionics — Transport Properties, Patras, Greece, Sept. 14 – 18, 2004. 相似文献
4.
Lithium fast ion conductors of the composition Li0.3La2/3Ti0.7P0.3−xVxO3.3 (LTV) based on mixtures of Li3xLa2/3−xTiO3 and LaPO4 were prepared by solid state reaction at high temperature (≈ 1300 °C). AC impedance measurements indicate total conductivities
of about 1 × 10−4 Scm−1 for compositions of x=0∼0.3 at room temperature with an activation energy of ≈18 kJ·mol−1 in the temperature range from 30 to 400 °C. X-ray powder diffraction patterns showed that the LTV system is composed of Li3xLa2/3−xTiO3 perovskite solid solution and LaP1−xVxO4 solid solution. 相似文献
5.
Lithium ion conductors of the overall composition LixLa2/3Ti1−xPxO3+x (hereafter referred to as LTP) based on La2/3TiO3 were prepared by solid state reaction at high temperature (1300 °C). AC impedance measurements indicate that the total conductivities
are of the order of 10−4 S·cm−1 when x=0.28 − 0.35 at room temperature and have an activation energy of 18 kJ·mol−1 in the temperature range from room temperature to 400 °C. X-ray powder diffraction patterns showed that the LTP system has
a complex composition, which contains the solid solution perovskite Li3xLa2/3−xTiO3 and LaPO4. 相似文献
6.
A new trivalent bismuth ion conducting solid electrolyte, (BixGe1 − x)4/(4 − x)Ta(PO4)3, was successfully developed by selecting the NASICON-type GeTa(PO4)3 as the mother solid. Although bismuth has two kinds of valence states of + 3 and + 5, it was clear that pure trivalent Bi3+ ion conduction, without any electronic conduction by a valence change of bismuth in the oxygen pressure range over 10− 3 Pa, was realized by selecting the crystal structure and constituents of the solid. 相似文献
7.
《Solid State Ionics》1986,21(3):231-238
Lithium ion conductors of composition Li9−4xZrx〈PO4〉3 (0.0 < x < 2.0) have been prepared by the conventional solid state reaction and also by a wet chemical method. X-ray diffraction patterns reveal identical crystallographic morphology for the compounds prepared by the two methods. However, they can be prepared and sintered at much lower temperatures by the wet chemical method. Their conductivities are also higher. Compared to pure Li3PO4, one of the end member of the series, the conductivity increases sharply with substitution of lithium by zirconium. The highest conductivity has been obtained in the composition Li1.8Zr1.8〈PO4〉3 (x = 1.8), prepared by the wet chemical method. The conductivity value of 10−3 ω−1 cm−1 is obtained at around 225°C with an activation energy of about 0.5 eV. 相似文献
8.
M. Barré F. Le Berre M-P. Crosnier-Lopez C. Galven O. Bohnké J-L. Fourquet 《Ionics》2009,15(6):681-687
The Li1−x
La
x
/3Zr2(PO4)3 NASICON-type compounds (0 ≤ x ≤ 1) have been synthesized in powder form by a sol-gel method and sintered for ionic conductivity measurements. In order
to improve the compactness of the ceramic without decomposition of the compound, several sintering processes have been tested
for one member of the solid solution (x = 0.6): the use of sintering aids (ZnO, B2O3, TiO2 and LiNO3), a ball-milling of the synthesized powder, a flash heating, high isostatic pressure, and spark plasma sintering. Finally,
a satisfactory compactness of 85% is obtained compared to the referenced value (63%) obtained by uniaxial and isostatic pressing.
The ionic conductivity study was performed by impedance spectroscopy. It shows that, despite the formation of vacancies, the
substitution Li+→ 1/3 La3+ + 2/3 □ has unfortunately no influence on the conduction for 0 ≤ x ≤ 0.7 since the ionic conductivity remains identical to the LiZr2(PO4)3 one. For higher x values, the ionic conductivity strongly decreases. 相似文献
9.
LiCo1−x
Mn
x
PO4/C cathode materials are selectively synthesized by a solvothermal method in ethylene glycol solvent using glucose, LiCl,
H3PO4, MnCl2·4H2O, and Co(NO3)2·6H2O as precursors. The obtained samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and
transmission electron microscopy (TEM) and the electrochemical performances are also evaluated using a LAND CT2001A battery
test system at room temperature. XRD result demonstrates the formation of LiCo1−x
Mn
x
PO4 solid solution and the enlarged channels are benefit for Li+ migration. SEM graph indicates that the particle size of LiCo0.5Mn0.5PO4/C is about several hundred nanometers and aggregates to large particles located in the range of 2–3 μm. TEM image illustrates
that the core/shell-structured LiCo0.5Mn0.5PO4/C solid solution is indeed obtained by this method. The high specific surface area (35 m2/g) of LiCo0.5Mn0.5PO4/C could make this solid solution contact with the electrolyte more sufficiently and benefit for Li+ transportation. The capacity, flat voltage, and cyclical stability of LiCo1−x
Mn
x
PO4/C are improved compared to LiMnPO4 and LiCoPO4 due to the improved electronic conductivity and lithium-ion conductivity which resulted from carbon coating and foreign element
incorporation. 相似文献
10.
Perovskite-type lithium fast ion conductors of Li3xLa0.67−xScyTi1−2yNbyO3 system were prepared by solid state reaction. X-Ray powder diffraction shows that perovskite solid solution form in the ranges
of x=0.10, y≤0.10. AC impedance measurements indicate that the bulk conductivities and the total conductivities are of the
order of 10−4 S·cm−1 and 10−5 S·cm−1 at 25 °C respectively. The compositions have low bulk activation energies of about 17 kJ/mol in the temperature ranges of
298 – 523 K and total activation energies of about 37 kJ/mol in the temperature ranges of 298 – 523 K. 相似文献
11.
Wanwimon Banlue Naratip Vittayakorn 《Applied Physics A: Materials Science & Processing》2008,93(2):565-569
The solid solution between the antiferroelectric PbZrO3 (PZ) and relaxor ferroelectric Pb(Co1/3Nb2/3)O3 (PCoN) was synthesized by the columbite method. The phase structure and thermal properties of (1−x)PZ–xPCoN, where x=0.0–0.3, were investigated. With these data, the ferroelectric phase diagram between PZ and PCoN has been established. The
crystal structure data obtained from XRD indicates that the solid solution PZ–PCoN, where x=0.0–0.3, successively transforms from orthorhombic to rhombohedral symmetry with an increase in PCoN concentration. The AFE→FE
phase transition was found in the compositions of 0.0≤x≤0.10. The AFE→FE phase transition shift to lower temperatures with higher compositions of x. The width of the temperature range of FE phase was increased with increasing amount of PCoN. It is apparent that the replacement
of the Zr4+ ion by (Co1/3Nb2/3)4+ ions would decrease the driving force for antiparallel shift of Pb2+ ions, because they interrupt the translational symmetry. This interruption caused the appearance of a rhombohedral ferroelectric
phase when the amount of PCoN was more than 10 mol%. 相似文献
12.
G. Grange M. Troccaz L. Eyraud F. Bauer 《Applied Physics A: Materials Science & Processing》1980,23(3):289-293
The mechanical stress-forced Ferroelectric F→Antiferroelectric AF transition energy conversion is reviewed. The temperature-composition
phase diagram of PbHf1−xTixO3+1%La2O3 is established. The composition of a suitable material such as a ternary solid solution of the Pb(Hf1−yZry)1−xTixO3+1%La2O3 type, characterized by a low transition pressure, is theoretically determined by a graphic construction using the Goldschmidt
factor. Experimental results on the prepared material are given. 相似文献
13.
Solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 was prepared by sol-gel method under different sintering conditions. The structural identification, surface morphology, electrochemical
window, ionic conductivity, and activation energy of the Li1.3Al0.3Ti1.7(PO4)3 sintered pellets were investigated by X-ray diffraction, scanning electron microscopy, cyclic voltammetry, and electrochemical
impedance spectroscopy. It is found that the sintering temperature and time have considerable effect on the properties of
the Li1.3Al0.3Ti1.7(PO4)3 sintered pellets. The Li1.3Al0.3Ti1.7(PO4)3 pellet sintered at 900 °C for 2 h is denser than the pellets sintered at other conditions. Different sintering conditions
result in the sintered pellet with different porosity. However, the sintering conditions have little effect on the electrochemical
window of Li1.3Al0.3Ti1.7(PO4)3. Among the Li1.3Al0.3Ti1.7(PO4)3 pellets sintered at various conditions, the pellet sintered at 900 °C for 2 h shows the highest ionic conductivity of 3.46 × 10−4 S cm−1 and the lowest activation energy of 0.2821 eV. 相似文献
14.
M. D. Durruthy-Rodríguez J. Costa-Marrero M. Hernández-Garcia F. Calderón-Pi?ar Célia Malfatti J. M. Yá?ez-Limón 《Applied Physics A: Materials Science & Processing》2011,103(2):467-476
In this work, visible photoluminescence was observed at room temperature in a sintered Pb(Zr1-xTix)1-y NbyO3\mathrm{Pb}(\mathrm{Zr}_{1-x}\mathrm{Ti}_{x})_{1-y} \mathrm{Nb}_{y}\mathrm{O}_{3} perovskite-type structure system, doped with Nb using the next excitation bands 325, 373 and 457 nm. The intensity and energy
of such emissions have been studied by changing the Nb concentration (0<y<0.01) and the Ti content (x), with x=0.20,0.40,0.53,0.60 and 0.80, on both sides of the morphotropic phase boundary (MPB) zone. The principal bands become visible
at energies of 1.73, 2.56 and 3.35 eV. The results reveal the role of the Nb5+ ion substitutions by Zr4+ or Ti4+ ions and the symmetry presented in the rhombohedral or tetragonal side of the MPB. Raman spectra which are similar for compositions:
20/80, 40/60 and 53/47 (tetragonal phases) show nine bands, centered around 137, 194, 269, 331, 434, 550, 612, 712 and 750
cm−1. The spectra for samples 60/40 and 80/20, rhombohedral phase, show significant differences, only six bands appear, centered
around 124, 209, 234, 330, 549 and 682 cm−1. In addition, optical absorption spectroscopy, structural and micro-structural measurements were carried out by using Uv-vis
spectroscopy, X-ray diffraction and scanning electron microscopy techniques, respectively. The experimental results of band
gap energy, e.g., in our samples are in accordance with the findings by J. Baedi et al. in the calculations of band structure,
energy gap and density of states for different phases of Pb(Zr1−x
Ti
x
)O3 using density functional theory (DFT). 相似文献
15.
J. Fedotova J. Kalinin A. Fedotov A. Sitnikov I. Svito A. Zaleski A. Jablonska 《Hyperfine Interactions》2005,165(1-4):127-134
The effect of oxygen-containing ambient arising at sputtering of granular nanocomposites (Fe0.45Co0.45Zr0.10)
x
(Al2O3)1−x
(30 at.%≤x≤65 at.%) on their magnetic state and phase composition has been investigated. It was shown that the presence of oxygen resulted
in the formation of oxide shells preventing the ferromagnetic interaction between Co0.45Fe0.45Zr0.10 nanoparticles and also the formation of metallic percolative net beyond the percolation threshold (as opposed to the films
prepared in pure argon atmosphere). 相似文献
16.
B. Mauvernay M. -P. Bichat F. Favier L. Monconduit M. Morcrette M. -L. Doublet 《Ionics》2005,11(1-2):36-45
Copper phosphide, Cu3P has been synthesized using a ceramic route, and its electrochemical behaviour versus lithium has been studied studied galvanostatic
and potentiodynamic measurements and in situ X-ray diffraction analysis. The insertion/extraction mechanism proceeds with
the formation of at least three different LixCu3−xP (x=1, 2, 3) phases. The electrochemical behaviour of Cu3P samples obtained from ceramic and solvothermal syntheses are compared to further understanding of the complex redox mechanism
occurring during insertion/extraction. First-principle electronic structure calculations show that discharge probably begins
with the formation of a solid solution LixCu3−yP (x<0.5).
Paper presented at the Patras Conference on Solid State Ionics-Transport Properties, Patras, Greece, Sept. 14 – 18, 2004. 相似文献
17.
18.
In this paper we discuss the nature of the ion conduction pathways in LixRb1−xPO3 glasses. Our investigations are based on a bond valence analysis of reverse Monte Carlo (RMC) produced structural models
in quantitative agreement with neutron and X-ray diffraction data. In a previous letter [11] we have shown that this approach
enables us to reproduce and understand the mixed alkali effect (MAE) directly from the structural models. The results have
shown that the drastic drop of the conductivity for an intermediate composition (x ≈ 0.5) is mainly caused due to the blocking
by immobile unlike cations, which is highly effective since the two types of alkali ions are randomly mixed and have distinctly
different conduction pathways of low dimensionality. Here, we explore the local dimensionality of the pathways and discuss
its implications for the network of pathways and the related ionic conductivity.
Paper presented at the Patras Conference on Solid State Ionics — Transport Properties, Patras, Greece, Sept. 14 – 18, 2004. 相似文献
19.
M.K. Tam 《Journal of Physics and Chemistry of Solids》2006,67(4):762-766
The corrosion behavior of Cu95−xZrxAl5 (x=40, 42.5 and 45 at.%) in 1 N HCl, 3 mass% NaCl and 1 N H2SO4 solutions was studied. As Zr content increases, the corrosion resistance is slightly enhanced. In order to improve the corrosion resistance of the Cu-Zr-Al glassy alloy, Nb was selected to substitute Cu. Although the supercooled liquid region ΔTx of the Cu-Zr-Al glassy alloys decreases with increasing Nb content, the alloys still retain high glass-forming ability and bulk glassy samples with 1.5 mm diameter can be obtained when up to 5 at.% Nb was added. It is found that the addition of Nb results in improvement of the corrosion resistance of the glassy Cu-Zr-Al alloys. 相似文献
20.
R. R. Levitskii I. R. Zachek L. N. Korotkov A. S. Vdovych S. I. Sorokov 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(10):1388-1393
Along with their electromechanical coupling coefficients, the longitudinal dielectric, piezoelectric and elastic characteristics
in ferroelectric KH2PO4 and antiferroelectric NH4H2PO4 crystals are calculated using a modified proton ordering model that considers piezoelectric coupling and the four-particle
cluster approximation. The possibility of detecting piezoactivity in solid solutions of K1 − x
(NH4)xH2PO4 is substantiated. 相似文献