Regensburg 2010 – scientific programme
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O: Fachverband Oberflächenphysik
O 77: Oxides and insulators: Epitaxy and growth
O 77.1: Talk
Thursday, March 25, 2010, 15:00–15:15, H42
Formation of a laterally nanostructured cobalt oxide — •Matthias Gubo, Christina Ebensperger, Wolfgang Meyer, Lutz Hammer, and Klaus Heinz — Lehrstuhl für Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen
In this study the growth of ultrathin cobalt oxide on a monolayer cobalt
and on a monolayer of a Co4Ir surface alloy - both prepared on a Ir(100) surface -
is investigated by means of low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM).
The oxide on a monolayer cobalt reveals a c(4x2) periodic LEED pattern.
Its structure consists of a compressively strained CoO(100) layer with
cobalt vacancies arranged in a c(4x2) periodicity equivalent to a Co3O4 stoichiometry of the film.
This structure is very different from the oxide on the bare iridium surface [1]indicating that
the internal structure of this cobalt oxide is strongly coupled to the underlying species of atoms
(cobalt or iridium, resp.). Accordingly, by growing the oxide on a well ordered Co4Ir lateral superlattice -
produced via decoration of the reconstructed Ir(5x1)-H phase [2] - the cobalt oxide monolayer
becomes laterally nanostructured.
So, the oxide’s growth appears to be strongly influenced by the local binding conditions to the substrate. In case of a laterally nanostructured substrate
the oxide is nanostructured, too.
M. Gubo et al., J. Phys.: Condens. Matter 21 (2009) 474211
[2] L. Hammer et al., PRL 91 (2003) 156101