Regensburg 2002 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 4: Oberfl
ächenreaktionen (I)
O 4.2: Vortrag
Montag, 11. März 2002, 11:30–11:45, H43
The Ag/O interface at elevated O2 pressures and temperatures — •Andreas Stierle, S. Kumaragurubaran, R. Streitel, K. Zhang und H. Dosch — Max-Planck Institut für Metallforschung, Heisenbergstraße 1, 70569 Stuttgart
The interaction of oxygen molecules with Ag surfaces has been studied since the advent of surface sciene due to its model character for gas / surface interactions. Ag plays in addition an important role as an industrial catalyst. Most of the former studies have been performed in the pressure range up to 10−6 mbar using standard surface science techniques. We will present surface x-ray diffraction experiments that have been performed in-situ up to a pressure of 10 mbar O2 and a temperature of 400∘C on beamline ID3 at the European Synchrotron Radiation Facility. The results indicate clearly that Ag(100) and Ag(111) surfaces undergo significant structural changes that are reversible with oxygen pressure. The resulting new structures are extremly unstable under UHV conditions and can not be observed by standard techniques like low energy electron diffraction.