Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 31: Nano structured materials III
MM 31.4: Vortrag
Donnerstag, 29. März 2007, 12:30–12:45, H4
Oxygen diffusion in fully dense nanocrystalline yttria-stabilized zirconia — •Harald Drings1, Ulrich Brossmann2, Hans-Eckhardt Schaefer1, Agnes Szoekefalvi-Nagy3, Heinz Dieter Carstanjen3, and Jürgen Fleig4 — 1Institut für Theoretische und Angewandte Physik, Univ. Stuttgart — 2Institut für Materialphysik, TU Graz, Österreich — 3Max Planck Institut für Metallforschung, Stuttgart — 4Institut für Chemische Technologien und Analytik, TU Wien, Österreich
It has been recently shown[1] that the oxygen diffusivity in the grain boundaries of n-ZrO2 · Y2O3 is strongly enhanced compared to the volume diffusivity. Therefore, nanocrystalline yttria-stabilized zirconia are a most promising material for the application as an oxygen ion conductor in gas sensors or solid oxide fuel cells. The oxygen diffusivity in n-ZrO2 · 9.5 mol % Y2O3 was studied by 18O Tracer diffusion and ERDA. In addition, the Zr diffusivity was studied by 95Zr Tracer diffusion to gain information about the reliability of future n-ZrO2 · Y2O3-based devices. The specimens were prepared by gas-phase synthesis of a nanocrystalline metal powder and subsequent oxidation, compaction and sintering using a optimized procedure[2] to obtain fully dense specimens with minimum distance between cracks of more than 500 µm, allowing both tracer diffusion and impedance studies, which is of particular interest within the framework of the Nernst-Einstein relationship.
[1] Knöner et. al., PNAS 100, 3870 (2003)
[2] Drings et. al., phys. stat. sol. (RRL) 1,1, R7 (2007)