Sökning: "pyrochlore"

Visar resultat 1 - 5 av 8 avhandlingar innehållade ordet pyrochlore.

  1. 1. Proton conductivity in acceptor-doped lanthanide based pyrochlore oxides

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :Karinh Eurenius; Göteborgs universitet.; Gothenburg University.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pyrochlore; Rietveld refinement; Proton conductivity; Electrical impedance spectroscopy; Concentration Cell Electromotive Force Method.;

    Sammanfattning : A high interest in developing new materials for SOFC applications in the temperature range of approximately 200–500 C has been growing lately. The lower activation energies for proton (H+) mobility can give higher conductivity in this temperature range. LÄS MER

  2. 2. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :Joakim Nyman; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

    Sammanfattning : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. LÄS MER

  3. 3. Inelastic light scattering of superconducting transition metal oxides

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :Joakim Holmlund; [2004]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pyrochlore; Raman spectroscopy; spin ladder; high tc; superconductuctivity;

    Sammanfattning : .... LÄS MER

  4. 4. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :Joakim Nyman; [2012]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER

  5. 5. Studies of systems related to high-Tc superconductors by electron microscopy and X-ray powder diffraction

    Detta är en avhandling från Stockholm : Stockholm University

    Författare :Ingrid Bryntse; Stockholms universitet.; [1992]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : New cuprate systems related to high temperature superconductors have been investigated and are reviewed. The synthesized samples have been studied mainly by transmission electron microscopy, energy-dispersive spectrometry and X-ray powder diffraction, in order to determine composition and structure of the formed phases. LÄS MER