Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 77: Oxides and insulators: Epitaxy and growth

O 77.6: Vortrag

Donnerstag, 25. März 2010, 16:15–16:30, H42

Comparing the Structure of Line Defects and Step Edges in the Alumina Film on NiAl(110) -- A Dynamic Force and Scanning Tunneling Microscopy Study — •Lars Heinke, Leonid Lichtenstein, Georg Hermann Simon, Thomas König, Markus Heyde, and Hans-Joachim Freund — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14196 Berlin, Germany

Thin metal oxide films, like aluminum oxide on NiAl(110), are often used as model systems in catalysis. It was found that line defects like step edges and anti phase domain boundaries (APDB) are particularly active sites for catalysis and, therefore, require detailed investigations. In this context, frequency modulated dynamic force microscopy (FM-DFM) and scanning tunneling microscopy (STM) are used to determine the atomic structure of the thin film and its defects in ultra high vacuum at 5 K [1]. The APDBs are orientated along two different directions, i.e. there exist two possible orientations of the film (domain A and B). A detailed analysis reveals that the step edges, which are uniformly distributed on the substrate before the film growth, prefer orientations along these angles. This suggests that the substrate is influenced by the growth of the thin film.

[1] G. H. Simon et al., New J. Phys. 11 (2009), 093009