Anharmonic contribution to the temperature dependence of photoemission core level spectroscopy of chemisorbed atoms: oxygen on Rh(110)
Abstract
High Energy Resolution X-ray Photoelectron Spectrocopy performed at a third generation synchrotron radiation source has been used to investigate the temperature dependence of the O1s and O2s core level photoemission signals from the O-(2x2)p2mg structure on Rh(110). This structure consists of chemisorbed oxygen atoms sitting in three-fold sites in zig-zag chains along the [1bar10] "missing-rows" of the reconstructed surface. With increasing temperature we observe an increase of the width of the peaks as previously observed for other adsorbates sistems. Even if the adsorption site of the O atoms is independent of temperature, we observe an anomalous and continuous shift of the photoemission peaks to lower binding energy. These new experimental findings are interpreted as due to anharmonic terms in the potential energy curve of the chemisorbed atoms. The study helps to the general understanding of core-level spectroscopy of atoms and molecules adsorbed on surfaces and opens a new way to probe the influence of very small effects such as anharmonic contributions in surface phenomena.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.G2810B