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1.
M. G. Zuev 《Russian Journal of Inorganic Chemistry》2010,55(1):93-95
Solid-phase interactions in the V2O5-Ta2O5-MoO3 system were studied. The formation of com- pounds TaVO5 and VTa9O25 in the V2O5-Ta2O5 binary system was verified. Tetragonal VTa9O25-base solid solutions of the general formula Ta5 + 4x
V5 − 4x
O25 (x = 0.25–1) and TaVO5-base solid solutions of the general formula Ta
x
Mo1 − x
V2 − x
O8 − 3x
(x = 0.625–1) were found to form. Subsolidus phase equilibria in the V2O5-Ta2O5-MoO3 were determined. 相似文献
2.
Phase relations in
the solid state in the FeVO4–Co3V2O8
system, in the whole range of components concentration have been studied.
It was found that the composition of the phase of the howardevansite type
structure, formed in the investigated system, corresponds with the Co2.616Fe4.256V6O24 formula. The phase of the lyonsite type structure
has a homogeneity range with the Co3+1.5xFe4–xV6O24 formula (0.476 formula (0.476<x<1.667).
The melting temperature and the volume of the unit cell of the lyonsite type
structure phase increases together with the rise of cobalt quantity contained
in it. Basing on the results of the DTA and XRD measurements a phase diagram
of the FeVO4–Co3V2O8
system up to the solidus line was constructed. 相似文献
3.
T. I. Krasnenko M. V. Rotermel’ S. A. Petrova R. G. Zakharov O. V. Sivtsova A. N. Chvanova 《Russian Journal of Inorganic Chemistry》2008,53(10):1641-1647
Phase relations in the Zn2V2O7-Cu2V2O7 system were studied by high-temperature X-ray diffraction and differential thermal analysis. The major phase constituents
of the system are solid solutions based on Zn2V2O7 and Cu2V2O7 polymorphs and their coexistence regions. The generation of α-Zn2 − 2x
Cu2x
V2O7 solid solution, where 0 ≤ x ≤ 0.30, leaves almost unchanged the stabilization temperature of the high-temperature zinc pyrovanadate phase. The α-Cu2 − 2x
Zn2x
V2O7 homogeneity range is 5 mol % Zn2V2O7. In the range 0.050 ≤ x ≤ 0.09 from 20 to ∼ 620°C, there is the two-phase field of α-Cu2V2O7 and β-Cu2V2O7 base solid solutions. At still higher temperatures, β-Zn2 − 2x
Cu2x
V2O7 and α-Cu2 − 2x
Zn2x
V2O7 coexist in the mixed-phase region. β-Zn2 − 2x
Cu2x
V2O7 solid solution, where 0 ≤ x ≤ 0.30, exists above 610 ± 5°C. The extent of the β′-Cu2V2O7-base solid solution is 9 to 65 mol % Zn2V2O7 at 615 ± 5°C, expanding to 0 mol % Zn2V2O7 with rising temperature.
Original Russian Text ¢ T.I. Krasnenko, M.V. Rotermel’, S.A. Petrova, R.G. Zakharov, O.V. Sivtsova, A.N. Chvanova, 2008, published
in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 10, pp. 1755–1762. 相似文献
4.
Large-scale Li1+x
V3O8 nanobelts were successfully fabricated using filter paper as deposition substrate through a simple surface sol–gel method.
The nanobelts were as long as tens of micrometers with widths of 0.4–1.0 μm and thickness of 50–100 nm. The nanobelts were
characterized by X-ray diffration (XRD), Fourier infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission
electron microscopy (TEM). The formation mechanism of the nanobelts was investigated, showing that the morphology of the nanobelts
is mainly determined by the calcination temperature. Electrochemical properties of the Li1+x
V3O8 nanobelts were characterized by charge–discharge experiments, and the results demonstrate that the Li1+x
V3O8 nanobelts exhibit a high discharge capacity (278 mAh g−1) and excellent cycling stability. 相似文献
5.
P. Tabero 《Journal of Thermal Analysis and Calorimetry》2007,88(1):37-41
Solid solution phases of a formula Fe8V10W16–xMoxO85 where 0≤x≤4, have been obtained, possessing a structure
of the compound Fe8V10W16O85.
It was found on the base of XRD and DTA investigations that these solution
phases melted incongruently, with increasing the value of x, in the temperature
range from 1108 (x=0) to 1083 K (x=4) depositing Fe2WO6
and WO3. The increase of the Mo6+
ions content in the crystal lattice of Fe8V10W16O85
causes the lattice parameters a=b contraction with cbeing
almost constant. IR spectra of the Fe8V10W16–xMoxO85 solid solution phases have been recorded. 相似文献
6.
K. Suryakala K. R. Marikkannu G. Paruthimal Kalaignan T. Vasudevan 《Journal of Solid State Electrochemistry》2007,11(12):1671-1677
LiMn2O4-based spinels are of great interest as positive electrode materials for lithium ion batteries. LiCo
x
Mn2−x
O4 (x = 0.0, 0.1, 0.2, 0.3, and 0.4) spinel phases have been synthesized by novel citric acid-modified microwave-assisted sol–gel
method. The structural properties of the synthesized products have been investigated by X-ray powder diffraction and scanning
electron microscopy. To improve the recharge capacity of Li/LiCo
x
Mn2−x
O4 cells, the electrochemical features of LiCo
x
Mn2−x
O4 compounds have been evaluated as positive electrode materials. The structural properties of Co-doped oxides are very similar
to LiMn2O4 electrode. Techniques like cyclic voltammetry, charge–discharge and cycle life are also used to characterize the LiCo
x
Mn2−x
O4 (x = 0.0, 0.1, 0.2, 0.3, and 0.4) electrodes. 相似文献
7.
Huaibing Sun Yungui Chen Chenghao Xu Ding Zhu Lihong Huang 《Journal of Solid State Electrochemistry》2012,16(3):1247-1254
Spinel powders of LiMn2−x
RE
x
O4 (RE = La, Ce, Nd, Sm; 0 ≤ x ≤ 0.1) have been synthesized by solid-phase reaction. The structure and electrochemical properties of these electrode materials
were characterized by X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge–discharge
experiment. The part substitution of rare-earth element RE for Mn in LiMn2O4 decreases the lattice parameter, resulting in the improvement of structural stability, and decreases the charge transfer
resistance during the electrochemical process of LiMn2O4. As a result, the cycle ability, 55 °C high-temperature and high-rate performances of LiMn2−x
RE
x
O4 electrode materials are significantly improved with increasing RE addition, compared to the pristine LiMn2O4. 相似文献
8.
YBaCo4O7 compound is capable to intake and release a large amount of oxygen in the temperature range of 200–400°C. In the present
study, the effect of Zn, Ga and Fe substitution for Co on the oxygen adsorption/desorption properties of YBaCo4O7 were investigated by thermogravimetry (TG) method. Due to fixed oxidation state of Zn2+ ions, the substitution of Zn2+ for Co2+ suppresses the oxygen adsorption of YBaCo4−xZnxO7. The substitution of Ga3+ for Co3+ also decreases the oxygen absorption capacity of YBaCo4−xGaxO7. This can be explained by the strong affinity of Ga3+ ions towards the GaO4 tetrahedron. Compared with Zn- and Ga-substituted samples, the drop of oxygen adsorption capacity is smallest for Fe-substituted
samples because of the similar changeability of oxidation states of Co and Fe ions. 相似文献
9.
V. A. Prituzhalov E. I. Ardashnikova V. A. Dolgikh A. M. Abakumov 《Russian Journal of Inorganic Chemistry》2011,56(3):313-324
Tysonite solid solutions Bi1−x
Ba
x
O
y
F3−x−2y
in the BiF3-BiOF-BaF2 system were obtained by solid-phase synthesis in sealed copper tubes in an argon atmosphere at 873 K with subsequent quenching.
The solid solutions were studied by X-ray diffraction, electron diffraction, and impedance spectroscopy. On the basis of X-ray
powder diffraction data, the homogeneity ranges of the tysonite solid solutions were determined and the scheme of their location
in the BiF3-BiOF-BaF2 system at 873 K was suggested. Aliovalent substitutions in both the cation and anion sublattices Ba2+ → Bi3+ and O2− → F− made it possible to vary the concentration of anion vacancies. It was found that, at a high concentration of anion defects
at 873 K, the hexagonal tysonite modification with space group P63/mmc is stable. With a decrease in the defect concentration, the trigonal tysonite modification with space group $
P\bar 3c1
$
P\bar 3c1
becomes stable. An ordered monoclinic tysonite-type modification BiO
y
F3 − 2y
(0.13 < y < 0.23) was revealed. For the homogeneity ranges of all tysonite phases, dependences of the unit cell parameters and conductivity
on the composition along the sections with a constant barium or oxygen content were reported. The most probable location of
oxygen anions and anion vacancies in the tysonite structure is discussed. 相似文献
10.
L. F. Brum Malta Marta Eloisa Medeiros 《Journal of Thermal Analysis and Calorimetry》2007,87(3):883-886
This work reports the study of Bi4V2–xBaxO11–1.5x (0.02≤x≤0.50)
series, which is a potential source of solid electrolytes to apply in oxygen
sensors. X-ray powder diffraction was used to point out the formation of major
ionic conductive phases and minor ones. The modifications of vanadate substructure
were probed, at short range, by Fourier-transform infrared spectroscopy. Differential
scanning calorimetry evidenced the formation of tetragonal γ phase, which
can be ionic conductive, for x=0.14. 相似文献
11.
G. Nenartaviciene K. Tõnsuaadu D. Jasaitis A. Beganskiene A. Kareiva 《Journal of Thermal Analysis and Calorimetry》2007,90(1):173-178
In this study the formation of chromium substituted YBa2Cu4O8 (Y-124) superconductors has been investigated by TG/DTA measurements. The YBa2(Cu1−xCrx)4O8 ceramics with nominal compositions of x=0.01, 0.03, 0.05, 0.10 and 0.20 have been prepared by an aqueous sol-gel method using aqueous mixtures of the corresponding
metal acetates and nitrates. Homogeneous precursor gels were obtained by complexing metal ions with tartaric acid. To assist
the interpretation of the results obtained the synthesis products were additionally characterized by X-ray powder diffraction
(XRD) and resistivity measurements. It was determined that doping the YBa2Cu4O8 phase with chromium has a strong effect on the phase purity and superconducting properties of the synthesis products. 相似文献
12.
Ca3Co4O9 powder was prepared by a polyacrylamide gel route in this paper. The effect of the processing on microstructure and thermoelectric
properties of Ca3Co4O9 ceramics via spark plasma sintering were investigated. Electrical measurement shows that the Seebeck coefficient and conductivity
are 170 μV/K and 128 S/cm, respectively, at 700 °C, yielding a power factor value of 3.70 × 10−4 W m−1 K−2 at 700 °C, which is larger than that of Ca3Co4O9 ceramics via solid-state reaction processing. The polyacrylamide gel processing is a fast, cheap, reproducible and easily
scaled up chemical route to improve the thermoelectric properties of Ca3Co4O9 ceramics by preparing the homogeneous and pure Ca3Co4O9 phase. 相似文献
13.
B. Das M. V. Reddy G. V. Subba Rao B. V. R. Chowdari 《Journal of Solid State Electrochemistry》2011,15(2):259-268
Nano-composites of SnO(V2O3)
x
(x = 0, 0.25, and 0.5) and SnO(VO)0.5 are prepared from SnO and V2O3/VO by high-energy ball milling (HEB) and are characterized by X-ray diffraction (XRD), scanning electron microscopy, and
high-resolution transmission electron microscopy techniques. Interestingly, SnO and SnO(VO)0.5 are unstable to HEB and disproportionate to Sn and SnO2, whereas HEB of SnO(V2O3)
x
gives rise to SnO2.VO
x
. Galvanostatic cycling of the phases is carried out at 60 mA g−1 (0.12 C) in the voltage range 0.005–0.8 V vs. Li. The nano-SnO(V2O3)0.5 showed a first-charge capacity of 435 (±5) mAh g−1 which stabilized to 380 (±5) mAh g−1 with no noticeable fading in the range of 10–60 cycles. Under similar cycling conditions, nano-SnO (x = 0), nano-SnO(V2O3)0.25, and nano-SnO(VO)0.5 showed initial reversible capacities between 630 and 390 (±5) mAh g−1. Between 10 and 50 cycles, nano-SnO showed a capacity fade as high as 59%, whereas the above two VO
x
-containing composites showed capacity fade ranging from 10% to 28%. In all the nano-composites, the average discharge potential
is 0.2–0.3 V and average charge potential is 0.5–0.6 V vs. Li, and the coulombic efficiency is 96–98% after 10 cycles. The
observed galvanostatic cycling, cyclic voltammetry, and ex situ XRD data are interpreted in terms of the alloying–de-alloying
reaction of Sn in the nano-composite “Sn-VO
x
-Li2O” with VO
x
acting as an electronically conducting matrix. 相似文献
14.
Petra Šulcová Jan Večeřa Pavel Bystrzycki 《Journal of Thermal Analysis and Calorimetry》2012,108(2):525-529
New environmentally inorganic pigments based on Bi2O3 doped by metal ions, such as Zr4+ and Dy3+ have been developed and characterized using the methods thermal analysis, X-ray powder diffraction, and spectral reflectance
data. The compounds having formula Bi2−x
Dy
x/2Zr3x/8O3 (x = 0.2, 0.6, 1.0, and 1.2) were prepared by the solid state reaction. Methods of thermal analysis were used for determination
of the temperature region of the pigment formation and thermal stability of compounds. The incorporation of doped ions in
Bi2O3 changes the color from yellow to orange and also contributes to a growth of their thermal stability. This property gives
a direction for coloring ceramic glazes. 相似文献
15.
As a result of solid-state reactions three cadmium vanadates(V) have been obtained, i.e. CdV2O6, Cd2V2O7 and Cd4V2O9. Melting temperature and the product of melting has been determined for Cd4V2O9. Thermal properties of the obtained cadmium
vanadates(V) have been reinvestigated. The phase equilibria being established in the CdO-V2O5 system over the whole components concentration range up to the solidus line were described. 相似文献
16.
L. V. Yakovkina T. P. Smirnova V. O. Borisov S. Jeong-Hwan N. B. Morozova V. N. Kichai A. V. Smirnov 《Journal of Structural Chemistry》2011,52(4):743-747
The results of the investigation of the chemical constitution and structure of (HfO2)
x
(Sc2O3)1−x
thin films are reported. The films are obtained by chemical vapor deposition (CVD) from hafnium 2,2,6,6-tetramethyl-3,5-heptandionate
(Hf(thd)4) and scandium 2,2,6,6-tetramethyl-3,5-heptandionate (Sc(thd)3) coordination compounds. It is demonstrated by powder X-ray diffraction and infrared spectroscopy that depending on the scandium
content in the films the structure is changed from monoclinic to cubic. Voltage-capacity dependences of test Al/(HfO2)
x
(Sc2O3)1−x
/Si structures are used to calculate the dielectric constant of the films. For the films with the cubic structure it is found
that k = 21, while for the films with the monoclinic structure k = 9. 相似文献
17.
Monika Bosacka 《Journal of Thermal Analysis and Calorimetry》2007,88(1):43-46
It has been demonstrated that Co2V2O7
and InVO4 react with each other forming a new compound
of the Co2InV3O11
formula, when their molar ratio is equal to 1:1, or among CoCO3,
In2O3 and V2O5,
mixed at a molar ratio of 4:1:3. This compound melts incongruently at the
temperature of 960±5°C, depositing crystals of InVO4.
It crystallizes in the triclinic system and the unit cell parameters amount
to: a=0.6524(6) nm, b=0.6885(5)
nm, c=1.0290(4) nm, α=96.5°, β=104.1°,
γ=100.9°, Z=2. The phase equilibria
being established in the Co2V2O7–InVO4
system over the whole components concentration range up to the solidus line
were described. 相似文献
18.
N. B. Babanly Z. E. Salimov M. M. Akhmedov M. B. Babanly 《Russian Journal of Electrochemistry》2012,48(1):68-73
The EMF method with a solid Cu+-conducting electrolyte of Cu4RbCl3I2 was sued to study the Cu-Tl-Te system in the temperature range of 300–420 K. A diagram of solid-phase equilibriums of this
system is constructed, partial molar functions of copper in alloys, standard thermodynamic functions of formation and standard
entropies of CuTlTe2, CuTl4Te3, Cu2TlTe2, Cu3TlTe2, Cu9TlTe5 triple compounds and Cu
x
Tl5 − x
Te3 solid solutions (0 < x < 1) are calculated. The obtained results confirmed the assumption as to the possibility of using this modification for the
EMF technique for thermodynamic studies of copper-containing triple systems, even if they contain a less noble component than
copper. 相似文献
19.
Ji-min Yang Yan Yao Run-zhi Zhang Ai-de Sun Bao-hui Li Hong-zhi Lu Qi-ying Xia 《Journal of solution chemistry》2009,38(4):429-439
Osmotic coefficients and water activities for the Li2B4O7+LiCl+H2O system have been measured at T=273.15 K by the isopiestic method, using an improved apparatus. Two types of osmotic coefficients, φ
S and φ
E, were determined. φ
S is based on the stoichiometric molalities of the solute Li2B4O7(aq), and φ
E is based on equilibrium molalities from consideration of the equilibrium speciation into H3BO3,B(OH)4− and B3O3(OH)4−. The stoichiometric equilibrium constants K
m
for the aqueous speciation reactions were estimated. Two types of representations of the osmotic coefficients for the Li2B4O7+LiCl+H2O system are presented with ion-interaction models based on Pitzer’s equations with minor modifications: model (I) represents
the φ
S data with six parameters based on considering the ion-interactions between three ionic species of Li+, Cl−, and B4O72−, and model (II) for represents the φ
E data based on considering the equilibrium speciation. The parameters of models (I) and (II) are presented. The standard deviations
for the two models are 0.0152 and 0.0298, respectively. Model (I) was more satisfactory than model (II) for representing the
isopiestic data. 相似文献
20.
D. Z. de Florio V. Esposito E. Traversa R. Muccillo F. C. Fonseca 《Journal of Thermal Analysis and Calorimetry》2009,97(1):143-147
The sintering behavior of gadolinia-doped ceria powders was studied by the master sintering curve (MSC). Dilatometric analyses
of powders produced by a soft chemical method were performed to provide the experimental data set for the construction of
the MSC. The assumed model provided good fittings of the MSC and the activation energy for the sintering of Ce1−x
Gd
x
O3−δ, with x = 0, 0.05, 0.1, and 0.2 were found to be in the 218–325 KJ/mol range, depending on the dopant content. The results supported
that both the nanometric size of the particles and the difference in ionic radii between Gd3+ and Ce4+ affects the sintering of Gd-doped CeO2. 相似文献