Sökning: "Neutron diffraction"

Visar resultat 21 - 25 av 129 avhandlingar innehållade orden Neutron diffraction.

  1. 21. Proton Conducting Ceramics; Synthesis, Characterization and Sample Cell Environments

    Författare :FRANCIS GACHAO KINYANJUI; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perovskites; neutron diffraction; Rietveld refinements; BaSnO3; in-situ cell; deuteron position; proton conduction; BaZrO3;

    Sammanfattning : Acceptor doped Perovskite ceramics have been shown to exhibit high levels of protonic conduction in humid atmospheres. However significant grain boundary resistance and long sintering times required to achieve sufficient grain size growth has hindered their widespread application as electrolyzers, fuel cells and gas separation membranes. LÄS MER

  3. 22. Structural Studies of Mn-X (X=Al, Bi): Permanent Magnetic Materials without Rare Earth Metals

    Författare :Hailiang Fang; Martin Häggblad Sahlberg; Peter Svedlindh; Samrand Shafeie; Linda Udby; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Synthesis; Magnetism; Diffraction.; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Sammanfattning : How to generate and use electricity in a more efficient way is a major challenge for humankind. In this context, permanent magnets play an important role within a very broad range of electric power applications. The strongest magnets used today are mainly based on alloys that contain rare-earth metals, which are neither economical nor sustainable. LÄS MER

  4. 23. Functional Oxide Materials exhibiting Ionic Conductivity for Future Energy Conversion Needs

    Författare :FRANCIS GACHAO KINYANJUI; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; neutron diffraction; perovskites; oxygen deficient perovskites; BaSnO3; Rietveld refinements; BaZrO3; in-situ cells; proton conduction; deuteron position; Ba3In2ZrO8;

    Sammanfattning : Fuel cells are electrochemical devices that transform the chemical energy in hydrogen and oxygen into electrical energy at high efficiencies and produce only water vapour emissions. Materials with the perovskite or fluorite structure types are commonly employed as the ion conducting ceramic electrolyte membranes in intermediate and high temperature fuel cells. LÄS MER

  5. 24. Structure, Dynamics and Thermodynamics of Liquid Water : Insights from Molecular Simulations

    Författare :Kjartan Thor Wikfeldt; Lars G. M. Pettersson; Francesco Sciortino; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Liquid water; supercooled water; diffraction; structure modeling; molecular dynamics; x-ray spectroscopy; EXAFS; SAXS; Physics; Fysik; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Water is a complex liquid with many unusual properties. Our understanding of its physical, chemical and biological properties is greatly advanced after a century of dedicated research but there are still many unresolved questions. LÄS MER

  7. 25. Crystallographic studies of non-equilibrium structural changes in cathode materials

    Författare :Olof Gustafsson; William Brant; Marnix Wagemaker; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diffraction; Crystallography; Li-ion battery cathode materials; Spinel; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Sammanfattning : Battery cathode materials are a key focus for improvement of Li-ion battery chemistries due their limits in terms of capacity and cost. During insertion and extraction of Li, many cathode materials exhibit structural changes, ranging from e.g. phase transitions to amorphization. LÄS MER