Showing papers by "Enrique Ruiz-Trejo published in 2009"
TL;DR: In this article, the electrical properties of dense samples of Ce0.9Gd0.1O2−δ with grain sizes in the range 91-252 nm were studied by impedance spectroscopy.
Abstract: Dense samples of Ce0.9Gd0.1O2−δ with grain sizes in the range 91–252 nm were prepared and their electrical properties studied by impedance spectroscopy. It was found that the bulk conductivity is not affected by grain size or atmosphere and that small grain sizes lead to a larger total resistance of the material. The most striking result corresponds to a sample sintered in wet air that exhibited electrical characteristics that hint clearly at the presence of proton conduction at temperatures below 200 °C.
47 citations
TL;DR: In this article, a study of the structure and electrical conductivity of Mg-doped and nominally pure CeNb3O9-δ was undertaken, which exhibits an orthorhombic crystal structure as determined by Rietveld refinement.
Abstract: In the search of new materials for solid oxide fuel cells, a study of the structure and electrical conductivity of Mg-doped and nominally pure CeNb3O9-δ was undertaken. This material exhibits an orthorhombic crystal structure as determined by Rietveld refinement. Through a combined study of 4-point DC and AC impedance spectroscopy, it was determined that the material presents oxygen ion conductivity, electron conductivity and electron-hole conductivity according to the partial pressure of oxygen and temperature in agreement with a simple defect chemistry model. Finally, some experiments seem to indicate the presence of proton conduction.
2 citations