| Numéro |
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
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|---|---|---|
| Page(s) | C2-499 - C2-500 | |
| DOI | https://doi.org/10.1051/jp4/1997068 | |
J. Phys. IV France 7 (1997) C2-499-C2-500
DOI: 10.1051/jp4/1997068
Surface and Bulk σ*(C-D) States in NEXAFS Spectra of Condensed Formic Acid Layers
H.I. Sekiguchi1, T. Sekiguchi2 and K. Tanaka31 Ekctrotechnical Laboratory, 1-1-4 Umezono, Tsuhuba 305, Japan
2 Department of Synchrotron Radiation Facility Project, Japan Atomic Energy Research Institute, Mai 319-11, Japan
3 Department of Materials Science, Hiroshima University, Higashi-Hiroshima 724, Japan
Abstract
C X-shell near edge X-ray absorption fine structure (NEXAFS) spectra of condensed layers of formic acid
(DCOOD) have been recorded using the CKW Auger electron yield (AEY) and the photon-stimulated ion desorption (PSID)
yield of D+ . It is found that the position of σ*(C-D) resonance in the AEY is much higher than that in the D+ PSID yield
which is similar to that in the AEY of formic acid monolayer. This indicates that PS1D-NEXAFS is extremely surface
sensitive while AEY-NEXAFS reflects a bulk state. The higher energy shift can be explained by the antibonding nature of
σ*(C-D) excited state. The obtained results demonstrate that excitation of a strongly antibonding molecular orbital shifts
to higher energy in the bulk compared with the surface by final-state interactions. These results have broad implications
for the assignments of NEXAFS peaks in other systems.
© EDP Sciences 1997