Sökning: "Rietveld refinements"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Rietveld refinements.
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
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
Sammanfattning : Proton conducting oxides can be beneficial as electrolyte materials in devices such as fuel cells, hydrogen sensors etc. Proton conducting fuel cells (PCFCs), utilising H2 as fuel, stand out as a promising technology for future clean energy generation. LÄS MER
Sammanfattning : Powder samples with the general composition (Tl,Hg)2(Ba,Sr)2(Sr,Ca)Cu2O8-d, abbreviated 2212, were synthesised by solid-state reaction of metal oxides in closed silica ampoules. Depending on the relative amounts of Ba, Sr, and Ca, the superconducting transition temperature, Tc, varied significantly (45-100 K). LÄS MER
Sammanfattning : Zirconium alloys are widely used in the nuclear industry because of their high strength, good corrosion resistance and low neutron absorption cross-section. However, zirconium has strong affinity for hydrogen, which may lead to hydrogen concentration build-up over time during a corrosion reaction when exposed to water. LÄS MER