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1.
O. S. Kaimieva V. V. Danilova D. A. Kruzhkov E. S. Buyanova S. A. Petrova 《Russian Journal of Electrochemistry》2017,53(8):852-858
Substituted lanthanum manganites with the general composition La1–x Bi x Mn1–y Fe(Ni,Cu)yO3 + δ and unit cells in rhombohedral (space group (sp. gr.) R-3c) and/or orthorhombic (sp. gr. Pnma) symmetry are synthesized and attested. They are characterized by permanent excessive oxygen nonstoichiometry within a single structure type at room temperature, independent of the dopant concentration. These materials are adequately mechanically compatible with bismuth niobates. The interval of their chemical compatibility with bismuth-containing compounds is limited by 700–800°C. In this region, the conductivity of composites of substituted lanthanum manganites and bismuth-containing electrolytes is higher as compared with individual compounds. The use of individual manganites or their composites as the electrodes in cells with bismuthcontaining electrolytes increases the total conductivity of the cells. 相似文献
2.
The Mn3s X-ray photoelectron spectra of manganites were studied. It was shown that for the formal valence of manganese from 3+ to 3.3+, the doping holes are O2p in character; as the valence of manganese increases further, the Mn3d states acquire holes. For La0.7Sr0.3MnO3, the Mn3p-3d resonance spectra provided information about the occupied and unoccupied Mn3d states, and the correlation energy U = 6.7 eV was determined experimentally. An analysis of X-ray dichroism on the L absorption spectra of three-dimensional La7/8Sr1/8MnO3 showed that the cooperative Jahn Teller distortion of the orthorhombic phase at 240 K was related to (x 2 ? z 2)/(y 2 ? z 2) type orbital ordering. 相似文献
3.
T. S. Sysoeva E. A. Asabina V. I. Pet’kov V. S. Kurazhkovskaya 《Russian Journal of Inorganic Chemistry》2009,54(6):829-839
Phase formation in the A1 + x Al x Ti2 ? x P3O12 (A = Li, Na, K, Rb, or Cs; 0 ≤ x ≤ 2.0) and B0.5(l + x)Al x Ti2 ? x P3O12 (B = Mg, Ca, Sr, or Ba; 0 ≤ x ≤ 2.0) systems was studied using X-ray powder diffraction, electron probe microanalysis, and IR spectroscopy. The following double and triple orthophosphates were found to exist: A1 + x Al x Ti2 ? x (PO4)3 with A = Li (0 ≤ x ≤ 0.3), Na (0 ≤ x ≤ 1.0), K (x = 0, 1.0, or 2.0), Rb (x = 0, 1.0, or 2.0), or Cs (0 ≤ x ≤ 1.0) and B0.5(l + x)Al x Ti2 ? x (PO4)3 with B = Mg and Ba (x = 0), Ca and Sr (0 ≤ x ≤ 0.2). These orthophosphates crystallize in the structure types of kosnarite, langbeinite, cesium titanium arsenate, potassium aluminum phosphate, or rubidium aluminum phosphate. Their crystal parameters were calculated. For CsTi2(PO4)3 (x = 0), Rietveld refinement was carried out: space group Ia \(\bar 3\) d, Z = 32, a = 19.909(5) Å, V = 7892(1) Å3. This compound has a framework structure. The framework is built of TiO6 octahedra and PO4 tetrahedra; eight- and 12-coordinated Cs+ cations populate interstices. 相似文献
4.
The subsolidus phase composition of the M2O-CdO-V2O5 systems with M = Li or Na is studied. Double orthovanadates MCdVO4 and MCd4(VO4)3 form solid solutions of composition Li1 ? 2x/3Cd x/3CdVO4 (0 ≤ x ≤ 1, orthorhombic space group Cmcm, modulation at x = 0.6) and Na3 ? 2x Cd3 + x (VO4)3 (0 ≤ x ≤ 0.10 and 0.30 ≤ x ≤ 1, orthorhombic space group Cmcm and Pn21 a or Pnma, respectively). In the range 0.10 < x < 0.30, the end-members of the solid solutions coexist. Isothermal sections of the systems are mapped. 相似文献
5.
O. N. Karpov M. V. Tomkovich E. A. Tugova 《Russian Journal of General Chemistry》2018,88(10):2133-2138
Nd1–xBixFeO3 nanocrystals with crystallite size 30?60 nm have been prepared under conditions of glycine–nitrate burning. Single-phase Nd1–xBixFeO3 nanocrystals are formed over the entire studied concentrations range if the glycine–nitrate synthesis is performed in excess of the oxidizer. Under these conditions, a continuous range of the Nd1–xBixFeO3 solid solutions (0 ≤ х ≤ 0.75) crystallized in the rhombic system (space group Pbnm) are formed without crystallization of the burning intermediates. The Nd1–xBixFeO3 solid solutions (х = 0.775, 0.8) crystallize in the rhombic system (space group Pbаm). 相似文献
6.
Yu. V. Emel’yanova E. N. Tsygankova S. A. Petrova E. S. Buyanova V. M. Zhukovskii 《Russian Journal of Electrochemistry》2007,43(6):737-741
Conditions for synthesizing single-phase solid solutions Bi4V2 ? x Cu x/2Ti x/2O11 ? x and Bi4 ? x/2V2 ? x/2Cu x/2Ti x/2O11 ? x/2 are studied. The sequence of phase transformations is determined. Possible domains of stability of polymorphic modifications and the overall conductivity as a function of temperature and composition are studied. The structure of the γ-modification is refined using Rietveld’s full-profile analysis. 相似文献
7.
E. S. Buyanova S. A. Petrova Yu. V. Emel’yanova N. A. Borodina R. G. Zakharov V. M. Zhukovskii 《Russian Journal of Inorganic Chemistry》2009,54(6):864-872
Existence boundaries, structure, and transport parameters were studied for Bi4V2 ? x Cu x/2Ti x/2O11 ? x solid solutions. Doping levels within x = 0.025–0.15 distort the C2/m crystal lattice (this lattice is characteristic of individual the Bi4V2O11 phase) and lowers its symmetry to triclinic. The solid solutions with 0.25 ≤ x ≤ 0.30 crystallize in tetragonal space group I4/mmm. High-temperature X-ray diffraction and dilatometry measurements for Bi4V2 ? x Cu x/2Ti x/2O11 ? x (x ≤ 0.35) solid solutions verified the existence of three structural varieties within 298–1023 K. Electrical conductivity of BICUTIVOX was studied by impedance spectroscopy as a function of temperature, composition, and oxygen partial pressure. Equivalent circuits of cells were analyzed. Features of electrical conductivity versus temperature for the structural varieties are noted. Above 873 K, the solid solutions samples with x = 0.05 have the highest conductivity. At lower temperatures, higher conductivities are in the solid solutions that retain the γ phase in the low-temperature region. The dominant oxygen-ion conduction mechanism was discovered in the solid solutions. 相似文献
8.
B. K. Kasenov M. O. Turtubaeva Sh. K. Amerkhanova R. N. Nikolov Sh. B. Kasenova Zh. I. Sagintaeva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(2):282-286
Temperature dependences of the heat capacity of cobalt manganites NdM2 I CoMnO5 (MI = Li, Na, and K) are studied by means of dynamic calorimetry in the range of 298.15?673 K. It is found that λ-shaped effects are observed on the C p ° ~ f (T) curve of cobalt manganites, due probably to second order phase transitions. Based on the experimental data, equations for the temperature dependences of the heat capacity of cobalt manganite are derived with allowance for the temperatures of phase transitions. The values of thermodynamic functions Н°(T)–Н°(298.15), S°(T), and Фхх(T) are calculated. 相似文献
9.
The effect of active fillers such as titanium nitrides TiN x , carbides TiC x , and carbonitrides TiC x N y (0.5 < x or x + y ≤ 1.0) on properties of polymeric composites based on thermostable binders PAIS-104, SFP-012 AK-30, and ED-20 is studied. 相似文献
10.
L. N. Mazalov Yu. P. Dikov N. A. Kryuchkova V. V. Sokolov I. Yu. Filatova E. A. Korotaev A. D. Fedorenko 《Journal of Structural Chemistry》2010,51(1):59
The charged state of atoms in layered cation-substituted disulfides CuCr1?x V x S2 (x = 0?0.4) was studied using X-ray photoelectron spectroscopy. The study was performed with polycrystalline powder and ceramic samples of chromium-copper disulfides. CuCr1?x V x S2 samples were shown to comprise differently charged atoms of chromium, copper and vanadium, the charged state of which varies with the concentration of vanadium cations (x). 相似文献
11.
N. I. Steblevskaya M. V. Belobeletskaya M. A. Medkov V. S. Rudnev 《Russian Journal of Inorganic Chemistry》2017,62(3):275-280
The promise of synthesis of europium and terbium polytantalates MTa x O y , where М = Eu, Tb; x = 7, y = 19; x = 5, y = 14; x = 3, y = 9 by low-temperature extraction-pyrolytic method has been shown. Luminescent properties of the prepared polytantalates have been assessed from excitation and luminescence spectra at 300 K. The dependence of luminescent characteristics of the studied rare earth metal polytantalates on the temperature and time of precursor pyrolysis has been established. 相似文献
12.
G. A. Buzanov G. D. Nipan K. Yu. Zhizhin N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2017,62(5):551-557
Phase equilibria involving LiMn2O4-, Li2MnO3-, LiMnO2-, Mn3O4-, and MnO-base solid solutions were studied with varied temperature and partial oxygen pressure. The \({P_{{o_2}}}\)–T and x–y projections of the P–T–x–y phase diagram of the Li–Mn?O system were constructed, as well as the key x–y isotherms of the Li2O–MnO–MnO2 quasi-ternary system. In some experiments, the authors’ hydride lithiation method was employed to prepare lithium-rich homogeneous three-component nonstoichiometric phases. 相似文献
13.
Continuous substitutional solid solutions between cobalt and nickel phosphates with varied degree of anion protonation were obtained: Co1?x Ni x HPO4·1.5H2O and (Co1?x Ni x )3(PO4)2·8H2O, where 0 ≤ x ≤ 1.00. The thermolysis of the solid solutions was studied by the example of Co1?x Ni x HPO4·1.5H2O. The phases synthesized were compared with the previously described continuous solid solution Co1?x Ni x (H2PO4)2·2H2O. 相似文献
14.
Phase relationships in the subsolidus region of the system Na2MoO4-MnMoO4-Cr2(MoO4)3 were studied by means of X-ray diffraction and differential-thermal analyses. The possibility of obtaining a variablecomposition phase Na1?x Mn1?x Cr1+x (MoO4)3 (0 ≤ x ≤ 0.5) and ternary molybdate NaMn3Cr(MoO4)5 was examined. The temperature dependence of the conductivity of the phase Na1?x Mn1?x Cr1+x (MoO4)3 was analyzed. 相似文献
15.
E. S. Buyanova O. S. Kaimieva A. N. Shatokhina M. V. Morozova Yu. V. Emel’yanova S. A. Petrova 《Russian Journal of Inorganic Chemistry》2016,61(4):470-476
Solid solutions Bi3Nb1–yWyO7 ± δ, Bi3Nb1–yVyO7 ± δ, Bi3Nb1–yFeyO7 ± δ (y = 0.1–0.5; Δy = 0.1), and Bi3–xYxNb1–yWyO7 ± δ (x = 0.05, 0.1; y = 0–0.3; Δy = 0.1) have been studied. The homogeneity ranges of the solid solutions and crystal-chemical parameters have been determined by means of X-ray powder diffraction. The electrical conductivity of sintered samples has been studied by impedance spectroscopy. The joint introduction of yttrium and tungsten into the niobium sublattice does not lead to an increase in the conductivity of solid solutions, and the change of the dopant type has no noticeable effect on this conductivity. 相似文献
16.
Z. F. Tomashik R. A. Denisyuk V. N. Tomashik A. S. Chernyuk I. M. Rarenko 《Russian Journal of Inorganic Chemistry》2009,54(6):881-884
Chemical etching of Cd1 ? x Mn x Te (0.04 < x < 0.5) solid solution (ss) single crystals in I2 + CH3OH etching mixtures was studied. Concentration and kinetic curves of etching rates were plotted. As the manganese concentration of the solid solution increases, the rates of their etching by iodine-methanol etchants increase, too. The etchant compositions and chemical-dynamic polishing protocols for Cd1 ? x Mn x Te single crystals were optimized. 相似文献
17.
E. S. Buyanova S. A. Petrova Yu. V. Emel’yanova A. L. Blinova M. V. Morozova V. M. Zhukovskii V. D. Zhuravlev 《Russian Journal of Inorganic Chemistry》2009,54(8):1193-1204
Existence boundaries, structure, and transport parameters of ultrafine powders were studied in Bi4V2 ? x Fe x O11 ? x (BIFEVOX) solid solutions. The details of synthesis of the solid solutions via liquid precursors are analyzed comparatively. In general, BIFEVOX formation via liquid precursors is similar to phase formation in solid-phase synthesis. With low iron levels (x = 0.05–0.1), solid solutions are formed in the monoclinic α phase (space group C2/m) The compositions with x = 0.125 and 0.15 are mixtures of α- and β phases. In the range 0.2 < x < 0.7, the Bi4V2 ? x Fe x O11 ? x solid solution has the structure of the γ phase of Bi4V2O11 (space group I4/mmm). The β phase in the system in question has a very narrow existence range in the vicinity of x = 0.175. The average particle sizes of the powders prepared by various methods are within 0.5–3 μm. In the powders prepared via liquid precursors, however, the distribution peak shifts toward smaller sizes, to 0.3–1 μm. Mechanical activation conserves the structure of the γ phase of BIFEVOX, and unit cell parameters change only insignificantly; however, the crystal lattice is slightly distorted. The electrical conductivity of BIFEVOX was studied as a function of temperature, preparation technology, and composition using impedance spectroscopy. Equivalent circuits of cells were analyzed. The conductivity of samples prepared by solution technology is always higher than for samples prepared by the solid-phase process. Features of electrical conductivity versus temperature for various phases are noted. All transitions on the conductivity curves match the features of linear thermal expansion curves. Compositions with doping levels x= 0.1–0.3 have the highest total conductivities. 相似文献
18.
V. G. Kostishin V. G. Andreev D. N. Chitanov A. G. Nalogin N. D. Ursulyak A. A. Alekseev A. V. Timofeev A. Yu. Adamtsev 《Russian Journal of Inorganic Chemistry》2016,61(3):279-283
The effects of the base composition and dopants on the saturation magnetization and coercivity of hexaferrites BaAlxFe12–xO19, SrAlxFe12–xO19, BaGaxFe12–xO19, SrGaxFe12–xO19, BaScxFe12–xO19 and SrScxFe12–xO19 have been studied. Isomorphic substitutions of Al2O3, Ga2O3, and Sc2O3 for Fe2O3 in barium and strontium ferrites are found to increase coercivity due to increasing crystallographic anisotropy constant and to reduce the saturation magnetization value. Processes controlling microstructure formation, specifically recrystallization processes, are shown to have a noticeable effect on the level of properties of the ferrites under study with the use of dopants. The most efficient dopants are boron, calcium, and silicon oxides, which provide the formation of relatively fine-grained structures. The increased coercivity upon doping with these dopants is also due to the formation of grain-boundary interlayers of a nonmagnetic glassy phase and the associated efficient retardation of moving domain walls. 相似文献
19.
The subsolidus region of the Ag2MoO4-MgMoO4-Al2(MoO4)3 ternary salt system has been studied by X-ray phase analysis. The formation of new compounds Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 (0 ≤ x ≤ 0.4) and AgMg3Al(MoO4)5 has been determined. The Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 variable-composition phase is related to the NASICON type structure (space group R \(\bar 3\) c). AgMg3Al(MoO4)5 is isostructural to sodium magnesium indium molybdate of the same formula unit and crystallizes in triclinic system (space group P \(\bar 1\), Z = 2) with the following unit cell parameters: a = 9.295(7) Å, b = 17.619(2) Å, c = 6.8570(7) Å, α = 87.420(9)°, β = 101.109(9)°, γ = 91.847(9)°. The compounds Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 and AgMg3Al(MoO4)5 are thermally stable up to 790 and 820°C, respectively. 相似文献
20.
E. I. Get’man T. A. Shul’gina S. N. Loboda L. Carrison 《Russian Journal of Inorganic Chemistry》2008,53(8):1342-1345
Isomorphic substitution of neodymium and gadolinium for calcium in synthetic hydroxovanadate Ca5 ? x M x (VO4)3(OH)1 ? x O x (M = Nd, Gd) is studied in the range 700–1000°C using X-ray powder diffraction, single-crystal X-ray diffraction (Rietveld technique), and IR spectroscopy. Single-phase solid solutions at 800°C are formed with x ≤ 0.35 for M(III) = Nd and x ≤ 0.3 for M(III) = Gd. With high x, the apatite solid solution coexists with Ca3(VO4)2, Nd2O3, and X phases. With increasing x in the homogeneous region, the intensity of the bands of stretching vibrations and librations of OH groups decrease. Single-crystal X-ray diffraction shows that neodymium and gadolinium substitute for calcium in solid solutions mostly in Ca(2) positions. 相似文献