[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: 69. Jahrestagung der Deutschen Physikalischen Gesellschaft (DPG), Berlin/D; 04.03.2005.

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
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. [J. Gustafson et al., submitted to Phys.Rev.B]