共查询到20条相似文献,搜索用时 31 毫秒
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.
P. Schwendt D. Dudášová J. Chrappová M. Drábik J. Marek 《Journal of Thermal Analysis and Calorimetry》2008,91(1):293-297
The compound [Ni(NH3)6][VO(O2)2(NH3)]2 was prepared and characterized by elemental analysis and vibrational spectra. The single crystal X-ray study revealed that
the structure consists of [Ni(NH3)6]2+ and [VO(O2)2(NH3)]− ions. As a result of weak interionic interactions V′···Op (Op-peroxo oxygen), ([VO(O2)2(NH3)]−)2 dimers are formed in the solid-state. The thermal decomposition of [Ni(NH3)6][VO(O2)2(NH3)]2 is a multi-step process with overlapped individual steps; no defined intermediates were obtained. The final solid products
of thermal decomposition up to 600°C were Ni2V2O7 and V2O5. 相似文献
3.
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
4.
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
5.
Zh. A. Kochkarov M. V. Khubaeva Z. L. Khakulov 《Russian Journal of Inorganic Chemistry》2011,56(5):783-786
This is the first study of the NaBO2-Na2CO3-Na2MoO4-Na2WO4 quaternary system by differential thermal analysis. Na2[MoO4(x)WO4(1 − x)] solid solutions in the quaternary system are found to not decompose. 相似文献
6.
Ling Pei Meiya Li Jun Liu Benfang Yu Jing Wang Dongyun Guo Xingzhong Zhao 《Journal of Sol-Gel Science and Technology》2010,53(2):193-198
Ferroelectric thin films of Nd and Mn co-doped bismuth titanate, Bi3.15Nd0.85Ti3−x
Mn
x
O12 (BNTM) (x = 0–0.1), were fabricated on Pt/TiO2/SiO2/Si(100) substrates by a sol–gel technique. The BNTM films had a polycrystalline perovskite structure and uniform and dense
surface morphologies. A lattice distortion was observed in the BNTM films due to Mn ion doping. The ferroelectric measurement
of the films indicated that the values of coercive field (E
c
) decreased gradually with the increase of the Mn content (x), however, the remanent polarization (P
r
) increase firstly and then decrease with the increase of x. The sample with x = 0.05 had optimum electrical properties and a maximum 2P
r
value. The 2P
r
and 2E
c
values of the film at a maximum applied electric field of 400 kV/cm were 38.3 μC/cm2 and 180 kV/cm, respectively. Moreover, this BNTM capacitors did not show fatigue behaviors after 1.0 × 1010 switching cycles at a frequency of 1 MHz, suggesting a fatigue-free character. The main reason for the increase of the 2P
r
and the decrease of the 2E
c
might be attributed to the lattice distortion in BNTM films due to Mn ion doping. 相似文献
7.
Mohammad El-khateeb Khalil J. Asali Ibrahim Jibril Anas Abuseni Helmar Görls Wolfgang Weigand 《Transition Metal Chemistry》2009,34(4):419-424
A controlled substitution reaction of the chlorine atoms of 1,3,5-benzenetricarbonyl trichloride by the organoiron fragment
(CpFe(CO)2S) has been achieved. The complexes CpFe(CO)2SCO-3,5-C6H3(COCl)2 (1), 1,3-[CpFe(CO)2SCO]2-5-C6H3COCl (2) and 1,3,5-[CpFe(CO)2SCO]3C6H3 (3) were prepared from the reaction of (μ-S
x
)[CpFe(CO)2]2 (x = 3, 4) with 1,3,5-C6H3(COCl)3 in a 1:1, 2:1, or 3:1 metal to ligand molar ratio. The reactions of (1) with amines, thiols, and carboxylic acids produce the trifunctional mono-iron complexes CpFe(CO)2SCO-3,5-C6H3(COY)2 [Y = NR2 (4), SR (5), OCOR (4)]. The X-ray structure determination of (1) is reported. 相似文献
8.
A. P. Tyutyunnik V. N. Krasil’nikov V. G. Zubkov L. A. Perelyaeva I. V. Baklanova 《Russian Journal of Inorganic Chemistry》2010,55(4):501-507
Compounds described as V2O3(XO4)2, where X = S or Se, were prepared from vanadium(V) oxide mixtures with concentrated sulfuric and selenic acids. The physicochemical properties of the products were studied; for V2O3(SeO4)2, the crystal structure was determined by powder X-ray diffraction and neutron diffraction, and its key differences from the structure of V2O3(SO4)2 were identified. V2O3(SeO4)2 crystallizes in the monoclinic system with the unit cell parameters a = 15.3831(2)Å, b = 5.54096(5)Å, c = 9.71644(7)Å, β = 111.886(1)°, V = 768.51Å3, space group C2/c (no. 15). 相似文献
9.
A. Yu. Ledneva S. B. Artemkina P. A. Stabnikov L. V. Yanshole V. E. Fedorov 《Journal of Structural Chemistry》2017,58(4):758-762
A new Mo2O3(dpm)4 compound (I) is synthesized by the interaction of Mo(CO)6 with 2,2,6,6-tetramethylheptanedione-3,5 (dpm). The structure of complex I determined by the XRD method is as follows: triclinic crystal system, space group P–1, a = 10.1780(7) Å, b = 10.1817(6) Å, c = 13.3255(9) Å, α = 110.562(2)°, β = 102.233(2)°, γ = 93.9041(19)°, V = 1248.17(14) Å3. The compound is characterized by IR spectroscopy, mass-spectrometry and thermogravimetric analysis (TGA). 相似文献
10.
Anna Blonska-Tabero 《Journal of Thermal Analysis and Calorimetry》2008,93(3):707-710
A new phase Cd4Fe7+xV9+xO37+4x, where −0.5<x<1.5, has been obtained in the solid-state in the FeVO4−Cd4V2O9 system. The temperature of incongruent melting and the unit cell volume of this phase decrease with decreasing the content
of cadmium. The IR spectrum and SEM image of the new phase are presented. 相似文献
11.
Kazuyuki Suzuki Kaori Nishizawa Takeshi Miki Kazumi Kato 《Journal of Sol-Gel Science and Technology》2007,42(3):251-256
(Y,Yb)MnO3 and HfO2 films were prepared using alkoxy-derived precursor solutions, and (Y,Yb)MnO3/HfO2/Si structures were fabricated. The thickness, surface uniformity and crystallinity of the HfO2 film affect the crystallization of Y0.5Yb0.5MnO3 films. The degree of c-axis orientation and crystallinity of the Y0.5Yb0.5MnO3 films were changed with preparation conditions of HfO2 films. It was difficult to obtain Y0.5Yb0.5MnO3 films with high crystallinity and high degree of c-axis orientation on the HfO2 films thinner than 10 nm. The degree of c-axis orientation and crystallinity of the Y0.5Yb0.5MnO3 films on HfO2 films were improved by using diluted HfO2 precursor solution in the case of 10 nm-thick HfO2 film. Following this, the capacitance-voltage (C-V) characteristics were improved. 相似文献
12.
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
13.
Y. Akishige H. Shigematsu T. Tojo H. Kawaji T. Atake 《Journal of Thermal Analysis and Calorimetry》2005,81(3):537-540
Summary Specific heats on the single crystals of Sr2Nb2O7, Sr2Ta2O7 and (Sr1-xBax)2Nb2O7 were measured in a wide temperature range of 2-600 K. Heat anomalies of a λ-type were observed at the incommensurate phase transition of TINC (=495 K) on Sr2Nb2O7 and at the super-lattice phase transition of TSL (=443 K) on Sr2Ta2O7; the transition enthalpies and the transition entropies were estimated. Furthermore, a small heat anomaly was observed at the low temperature ferroelectric phase transition of TLOW (=95 K) on Sr2Nb2O7. The transition temperature TLOW decreases with increasing Ba content x and it vanishes for samples of x>2%. 相似文献
14.
Electrical conductivity in the monoclinic Li2TiO3, cubic Li1.33Ti1.67O4, and in their mixture has been studied by impedance spectroscopy in the temperature range 20–730 °C. Li2TiO3 shows low lithium ion conductivity, σ300≈10–6 S/cm at 300 °C, whereas Li1.33Ti1.67O4 has 3×10–8 at 20 °C and 3×10–4 S/cm at 300 °C. Structural properties are used to discuss the observed conductivity features. The conductivity dependences
on temperature in the coordinates of 1000/T versus loge(σT) are not linear, as the conductivity mechanism changes. Extrinsic and intrinsic conductivity regions are observed. The change
in the conductivity mechanism in Li2TiO3 at around 500–600 °C is observed and considered as an effect of the first-order phase transition, not reported before. Formation
of solid solutions of Li2–
x
Ti1+
x
O3 above 900 °C significantly increases the conductivity. Irradiation by high-energy (5 MeV) electrons causes defects and the
conductivity in Li2TiO3 increases exponentially. A dose of 144 MGy yields an increase in conductivity of about 100 times at room temperature.
Electronic Publication 相似文献
15.
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
16.
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
17.
E. Yu. Pikalova V. G. Bamburov A. A. Murashkina A. D. Neuimin A. K. Demin S. V. Plaksin 《Russian Journal of Electrochemistry》2011,47(6):690-696
CeO2-based solid solutions with a fluorite structure are promising materials as electrolytes of medium-temperature electrochemical
devices: electrolytic cells, oxygen sensors, and solid oxide fuel cells. In this work, studies are presented of the effect
of the dopant cation radius and its concentration on the physico-chemical properties of the Ce1 − x
Ln
x
O2 − δ solid solutions (x = 0–0.20; Ln = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb) and also of multicomponent solid solutions of Ce1 − x
Ln
x/2Ln′
x/2O2 − δ (x = 0–0.20; Ln = Sm, La, Gd and Ln′ = Dy, Nd, Y) and Ce1 − x − y
Sm
x
M
y
O2 − δ (M = Ca, Sr, Ba) obtained using the solid-phase synthesis technique. Electric properties of the samples were studied in the
temperature range of 623–1173 K and in the oxygen partial pressure range of 0.01–10−22 MPa. The values of oxygen critical pressure ( pO2 * )\left( {p_{O_2 }^* } \right) are presented, at which the ionic and electron conductivity values are equal. The values were calculated on the basis of
experimental dependences at 1023 K at the assumption that the ionic conductivity value is determined only by the dopant concentration
and its effective ionic radius and is independent of the oxygen partial pressure. 相似文献
18.
Danielle M. Chisholm J. Scott McIndoe Gabriella Bodizs Wee Han Ang Rosario Scopelliti Paul J. Dyson 《Journal of Cluster Science》2007,18(1):303-318
Reaction of [Ru6C(CO)16]2− with an excess of AgX (X = Cl, Br or I) affords heteronuclear clusters of formula [{Ru6C(CO)16Ag2X}2]2− in 80% yield, which for X = I and X = Br/Cl were crystallographically characterised. The formation of the cluster was followed
in solution using electrospray ionisation mass spectrometry (ESI-MS), which revealed the presence of a wide range of clusters
with the general formula [{Ru6C(CO)16}
x
Ag
y
X
z
](2x−y+z)− where x = 1 or 2, y = 1, 2, 3 or 4 and z = 0, 1 or 2. The high yield of the product despite the evident complicated solution speciation is attributed to selective
crystallisation of the observed compound driving the equilibrium toward this product. 相似文献
19.
The synthesis of new compounds based on Bi2O3
is investigated because they can be used as new environmentally friendly inorganic
pigments. Chemical compounds of the (Bi2O3)1–x(Er2O3)x type were synthetized.
The host lattice of these pigments is Bi2O3 that is doped by Er3+
ions. The incorporation of doped ions provides interesting colours and contributes
to an increase in the thermal stability of these compounds. The simultaneous
TG-DTA measurements were used for determination of the temperature region
of the pigment formation and thermal stability of pigments. 相似文献
20.
Differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) were used to study the thermal behaviour of (50-x)Na2O-xTiO2-50P2O5 and 45Na2O-yTiO2-(55-y)P2O5 glasses. The addition of TiO2 to the starting glasses (x=0 and y=5 mol% TiO2) resulted in a nonlinear increase of glass transition temperature and dilatation softening temperature, whereas the thermal
expansion coefficient decreased. All prepared glasses crystallize under heating within the temperature range of 300–610°C.
The contribution of the surface crystallization mechanism over the internal one increases with increasing TiO2 content. With increasing TiO2 content the temperature of maximum nucleation rate is also gradually shifted from a value close to the glass transition temperature
towards the crystallization temperature. X-ray diffraction measurements showed that the major compounds formed by glass crystallization
were NaPO3, TiP2O7 and NaTi2(PO4)3. The chemical durability of the glasses without titanium oxide is very poor, but with the replacement of Na2O or P2O5 by TiO2, it increases sharply. 相似文献