Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 50: Oxide and Insulator Surfaces I
O 50.8: Vortrag
Mittwoch, 2. April 2014, 12:15–12:30, WIL A317
In-situ x-ray investigation of solid oxide fuel cell model electrodes — •Sergey Volkov1, 2, Markus Kubicek3, Vedran Vonk1, Dirk Franz1, 2, Jürgen Fleig3, and Andreas Stierle1, 2 — 1Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany — 2Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany — 3Institut für Chemische Technologien und Analytik, Technische Universität Wien, 1060 Vienna, Austria
The performance of high temperature solid oxide fuel cell (SOFC) electrodes depends strongly on the structure and composition of yttria stabilized zirconia (YSZ) surfaces. In addition, on the fuel cell cathode side the interface between the perovskite electrode and the YSZ electrolyte plays an important role during the oxygen incorporation process. Our studies focus on the cathode side of SOFCs, which is mimicked by the YSZ (100) surface, as electrolyte, and pulsed laser deposition grown La0.8Sr0.2MnO3, as electrode, were studied. In order to track structural changes in-situ surface x-ray diffraction experiments were performed at the ESRF, beamline ID03. A special x-ray diffraction chamber was developed, which allows contacting the electrode and applying a controlled voltage across the electrolyte. Anomalous scattering at the Y and Zr K-edges was used to enhance the scattering contrast. The analysis of the crystal truncation rod data has revealed a noticeable change in intensity depending on different oxygen pressure, temperature and voltage conditions. These intensity changes mostly refer to the changes in the composition and vacancy concentration below the electrode, what will be presented in detail.