[Zurück]

W. Hofer, C. Klein, M. Schmid, P. Varga, L. Köhler, G. Kresse, J. Gustafson, A. Mikkelsen, M. Borg, J.N. Andersen, E. Lundgren:
"Structure of thin oxide film on Rh(100)";
Poster: 11th Europ. Conf. on Applications of Surface and Interface Analysis (ECASIA´05), TU Wien; 27.09.2005.

We have studied the surface oxide of Rh(100) with different experimental and theoretical methods:
STM (scanning tunneling microscopy), LEED (low energy electron diffraction), HRCLS (high
resolution core level spectroscopy) and DFT (density functional theory). The HRCLS measurements
indicated a trilayer RhO2 structure with two oxygen layers and one Rh layer in-between. STM and
quantitative LEED revealed a close-to-hexagonal surface with a c(8×2) periodicity. In order to coincide
with the square Rh(100) substrate, the hexagonal oxide overlayer is slightly distorted, resulting
in a c(8×2) structure. The structural details were obtained by quantitative LEED (Pendry R-factor
= 0.16) and DFT calculations. It was found that every seventh of the lower O atoms of the trilayer
surface oxide resides in on top positions of the Rh(100) substrate. Ab initio DFT calculations give
almost perfect agreement with the LEED results in all atomic coordinates. We therefore regard the
trilayer surface oxide model as confirmed and thus the oxygen induced c(8×2) structure as solved [1].