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Poly(ethylene oxide) (PEO) based-polymeric solid electrolytes are of growing interest for their applications in electrochemical devices. Their major limitations are structural and electrochemical stability, and low cationic transport number. A possible response to these problems is given by composite or nanostructured materials. We present sol-gel synthesis, thermal and electrical characterization of new electrolytes made of a composite glass-polymer matrix doped with LiClO4 and LiBF4. Emphasis to the critical aspects of preparation is given. We obtain a conductivity at room temperature better than 10−5 ohm−1 cm−1, which is high enough to envisage technological applications.

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The oxidation-reduction behaviour of transition metal and rare earth oxide systems in oxygen potential controlled atmospheres was investigated by means of a solid electrolyte-based coulometric technique (SEC) in carrier gas mode to obtain information concerning the extent of oxygen stoichiometry, thep-T-x diagram of any mixed oxide phase, the kinetics of the oxygen exchange and the phase transitions.

The direct coupling of SEC and electrical conductivity measurements provides further information about the relationship between oxygen deficiency and conductivity, especially as concerns the oxygen mobility and the transition from ionic to mixed ionic/electronic conductivity in any system.

In the fluorite-type phases PrO2−x, Ce0.8Pr0.2Oy−x and Ce0.8Sr0.08Pr0.12Oy−x, the higher oxidation state of Pr is stabilized and the electrical conductivity increases in this sequence. The perovskite-type phase Sr1−yCeyFeO3−x, shows transitions and a second phase reflected in the temperature-programmed spectrum of this substance. The electrical conductivity of Sr0.9Ce0.1FeO3−x changes fromn-type top-type with increasing oxygen pressure.

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Galvanic cells of the type (C+Cl2)(NaCl(s))(MCl2(s))(C+Cl2) give e. m. f. 's above 280°, which are due to the formation of ternary chlorides NanMCln+2. By the change in slope of continuously measured e.m.f.vs. T curves, the temperatures of solid-state reactions in systems NaCl-MCl2 can be found. This method was applied for the systems of NaCl with NiCl2, CoCl2 and CdCl2, and for KCl-NiCl2. With the exception of the system NaCl-NiCl2, all phase diagrams must be corrected.

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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−xGdxO3−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.

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The purpose of this work was to investigate the influence of titanium and yttrium dopants on chemical stability of selected Ba(Ce1−xTix)1−yYyO3 compounds. The presented results are the part of wider research concerning the crystallographic structure, microstructure, electrical and transport properties of these groups of materials. Samples of Ba(Ce1−xTix)1−yYyO3 with x=0.05, 0.07, 0.10, 0.15, 0.20, 0.30 and y=0.05, 0.10, 0.20 (for x=0.05) were prepared by solid-state reaction method. Initially, differential thermal analysis (DTA) and thermogravimetry (TG) were used for optimization of preparation conditions. Subsequently, DTA-TG-MS (mass spectrometry) techniques were applied for evaluation of the stability of prepared materials in the presence of CO2. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results were used to determine the phase composition, structure and microstructure of materials and to assist the interpretation of DTA-TG-MS results. The strong influence of Ti and Y dopants contents (x and y) on the properties was found. The introduction of Ti dopant led to the improvement of chemical stability against CO2. The lower Ti concentration the better resistance against CO2 corrosion was observed. Doping by Y had the opposite effect; the decrease of chemical stability was determined. In this case the higher Y dopant concentration the better resistance was observed. The attempt to correlate the influence of dopant on structure and chemical stability was also presented.

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The phase transition and the crystal structures of CuITe were investigated by differential thermal analysis and X-ray powder diffraction measurements in the temperature range between 300 and 683 K. The new phase transition in CuITe was observed at 592 K. The enthalpy of transition is ΔH=0.125 kJ mol-1. The new phase above 592 K belongs to tetragonal system with the space group I41 /amd.

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The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m2g-1 instead of aerosil with one of 175 m2g-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended.

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A set of phase diagrams for the systems CuX–AlkX (where Alk=Li, Na, K, Rb or Cs and X=Cl, Br or I) is given, basing on authors investigation and selected literature data. Sizes and valences of ions involved in Coulombic and polarization interactions were considered as main factors affecting phase equilibria. An increasing tendency for compound formation was noted in series Na→K→Rb→Cs, Na→Li and I→Br→Cl. The most strongly represented are compounds of the formulas AlkCu2X3 and Alk2CuX3.

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Investigations on the thermal decomposition of FeSO4H2O-BaO2 mixtures were carried out under isothermal conditions by using simultaneously solid electrolyte cell (EMF-method). Evoked interactions producing oxygen in the temperature range 553-673 K were established by means of a solid electrolyte oxygen analyzer. Based on Mssbauer spectroscopy data and X-ray analysis it was proved that these reactions were associated with the release of oxygen from barium peroxide, oxidation of ferrosulphate-monohydrate to FeOHSO4, and formation of barium ferrites such as BaFe2O4 and BaFe12O19.

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The results of comparative thermodynamic study of GaSb-Sn system are presented in this paper. Calorimetric measurements according to Oelsen's method and EMF measurements with zirconia as solid electrolyte were used for experimental investigation, while Chou's general solution model, Toop, Kohler and Muggianu methods were used for predicting thermodynamic characteristics in this system. Also, phase diagram of this quasibinary system, determined by DTA and optical microscopy, is presented.

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