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Doping Zirconia with Yttria (YSZ) to stabilize the crystal into a cubic structure, results in the introduction of oxygen vacancies within the lattice which allows for O2- ion conduction at high temperatures. For this reason it is often used in the anode and electrolyte in solid oxide fuel cells (SOFC). Fundamental studies of this application are generally performed in ultra-high vacuum (UHV) by building model anodes from single crystal YSZ upon which the catalytic metal is deposited. It is well known for other applications that the support surface morphology has the ability to influence metal nucleation, mobility, and sintering behaviour. Therefore control and characterization of the surface is crucial in order to perform rigorous experiments with reproducible data.
Results of SPM/XPS studies of the YSZ (100) surface, and the surprising richness of nano-structures formed as a consequence of manufacturing and intrinsic defects are presented. Further these defects will be shown to interact at high temperatures with such useful results as surface templating and the formation of nano-wires. The surface templating being the result of etch pit formation and mobility while the growth of nano-wires are believed to be the result of the linear organization of oxygen vacancies, similar to those seen for CeO2, which in turn react with surface carbon producing ZrC line defects. Studies of the growth of these nanostructures, their interaction with metal, and their modification or elimination through ion bombardment and annealing are discussed.
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