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Ionic Conductors (ionic + conductor)
Selected AbstractsEnergetics of Formation and Oxidation of Microporous Calcium Aluminates: A New Class of Electrides and Ionic Conductors.CHEMINFORM, Issue 3 2006Olga Trofymluk Abstract For Abstract see ChemInform Abstract in Full Text. [source] Solid-State SO2 Sensor Using a Sodium-Ionic Conductor and a Metal,Sulfide ElectrodeINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2006Youichi Shimizu All solid-state sulfur oxides (SOx) sensor devices combined with a sodium ionic conductor (Na5DySi4O12) disk and metal sulfide-sensing electrodes synthesized via solution routes have been systematically investigated for the detection of SO2 in the range of 20,200 ppm at 150,400°C. Among the various sulfide-sensing electrodes tested, the metal monosulfide-based electrodes gave good SO2 sensitivity at 400°C. The Pb1,xCdxS (x=0.1, 0.2)-based solid electrolyte sensor element showed the best sensing characteristics, i.e., the EMF response was almost linear to the logarithm of SO2 concentration in the range between 40 and 400 ppm, with a 90% response time to 100 ppm SO2 of about 3,15 min, and also showed high selectivity to SO2 at 400°C. [source] 17O NMR in room temperature phase of La2Mo2O9 fast oxide ionic conductorMAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2005Joel Emery Abstract A room temperature 17O NMR study of La2Mo2O9, a fast oxide ionic conductor exhibiting a phase transition at 580 °C between a low-temperature ,-phase and a high-temperature ,-phase, is presented. Four partly overlapping quasi-continuous distributions of oxygen sites are evidenced from 1D magic angle spinning (MAS) and 2D triple quantum MAS NMR experiments. They can be correlated with the three oxygen sites O1, O2 and O3 of the high-temperature crystal structure. The low-temperature phase is characterized by two distributed sites of type O1, which proves that the symmetry is lower than in the cubic high-temperature phase. Two-dimensional experiments show that there is no dynamic exchange process, on the NMR time-scale, between the different oxygen sites at room temperature, which agrees well with conductivity results. Copyright © 2005 John Wiley & Sons, Ltd. [source] Phase transitions and transport phenomena in Li0.25Cu1.75Se superionic compoundPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 15 2004M. Kh. Abstract Phase transformation points in Li0.25Cu1.75Se mixed electronic,ionic conductor have been determined by calorimetric, conductometric and thermoelectric measurements. The phase transformation (PT) from triclinic to monoclinic occurs at 403,413 K. At 503,515 K the monoclinic phase is followed by a rhombohedral modification. Both of these PTs are accompanied by drops on the calorimetric curve. At about 653 K observed anomalies in the temperature dependencies of the ionic conductivity, of the chemical diffusion coefficient and the jump of the ionic Seebeck coefficient have been induced by the PT to hexagonal phase. Neutron diffraction studies reveal the cubic structure of Li0.25Cu1.75Se compound (with space group Fm3m) at 773 K. The corresponding PT causes anomalies in the electrical and diffusion properties at 703,713 K. Cu ions are statistically distributed over tetrahedral and trigonal voids in an Fm3m cage; lithium ions randomly occupy 32(f) positions. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A Thermoplastic Gel Electrolyte for Stable Quasi-Solid-State Dye-Sensitized Solar Cells,ADVANCED FUNCTIONAL MATERIALS, Issue 15 2007H. Wu Abstract Dye-sensitized solar cells (DSSCs) are receiving considerable attention as low-cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11,% has been achieved, but potential problems in sealing the cells and the low long-term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long-term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40,wt,% poly(ethylene glycol) (PEG) as the polymeric host, 60,wt,% propylene carbonate (PC) as the solvent, and 0.65,M KI and 0.065,M I2 as the ionic conductors, a TPGE with a conductivity of 2.61,mS,cm,2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light-to-electrical-energy conversion efficiency of 7.22,% under 100,mW,cm,2 irradiation. The present findings should accelerate the widespread use of DSSCs. [source] Total cluster energy calculation of lithium ion conductors by the DV-X, methodINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 12 2009Y. Kowada Abstract Recently, several programs for the total cluster energy calculation have been developed in the DV-X, method. In this study, we have calculated and compared total cluster energies of several diatomic molecules and model clusters of ionic conductors. The total cluster energies of diatomic molecules are minimum near the equilibrium atomic distance of each molecule though the absolute value of the total cluster energy was slightly different from each other. In the case of the model cluster of the Li3N crystal, which is one of the typical Li ion conductors, we have obtained the energy change as a function of the site during the movement of a Li ion. The energy change with the movement of the Li ion along the conduction path was considerably smaller than along other paths, consistent with the results by the band calculation and experiments. The total cluster energy calculation method was useful enough for the discussion of the cluster energy. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Characterization of Electrical Properties of Li(FexAl1,x)5O8 Solid Solutions by Impedance SpectroscopyJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2000Shuichi Arakawa To examine polaronic transport properties in Li(FexAl1,x)5O8 spinel solid solutions, a scaling analysis for their conductivity spectra and modulus spectra was performed. As in the case of ionic conductors, two significant parameters of a crossover frequency and a power-law exponent were extracted from the conductivity spectra which displayed the universal dynamic response behavior. Both the mobility and the concentration of carriers were successfully determined from the crossover frequency. The power-law exponent and the stretching parameter obtained from the modulus spectra varied with composition, implying that the increase in Fe concentration would enhance the Coulomb interactions between small polarons. [source] Hexacopper(I) phosphorus(V) bromide penta(selenide/sulfide), Cu6P(Se0.7S0.3)5BrACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2008A. Gagor This work illustrates possible diffusion paths for CuI ions in a highly disordered structure of a superionic conductor of the argyrodite family. The Cu6P(Se0.7S0.3)5Br cubic structure is built from a [P(Se0.7S0.3)5Br] framework in which CuI ions are distributed in various tetrahedral, triangular and linear sites. There are two types of disorder in the structure. The first type results from the fact that there are fewer CuI ions than the number of positions available for them in the unit cell. The second type is due to the static distribution of Se and S atoms in the [P(Se0.7S0.3)5Br] framework. The title compound is a solid solution of two efficient ionic conductors, namely Cu6PSe5Br and Cu6PS5Br, in which high ionic conductivity results from order,disorder phenomena in the copper substructure. To shed light on the distribution of CuI ions in disordered Cu6P(Se0.7S0.3)5Br, we refined their positions using a combination of a nonharmonic approach and a split-atom model. At room temperature, CuI ions show strong anharmonic vibrations along the edge of the (Br)4 tetrahedra. The probability density functions of the CuI ions overlap and reveal possible diffusion paths. [source] | |||||||||||||