J. Phys. IV France 7 (1997) C2-531-C2-532
NEXAFS Investigations on Highly-Ordered Ultrathin Films of DMe-DCNQI on Single Crystal SurfacesM. Bässler1, R. Fink1, Chr. Buchberger1, D. Gador1, C. Heske1, J. Müller1, P. Väterlein1, J.U. von Schütz2 and E. Umbach1
1 Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzhurg, Germany
2 3 Physikal. Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
DMe-DCNQI forms highly-ordered ultrathin films on various single crystal surfaces. NEXAFS reveals flat lying molecules for a l investigated film thicknesses (up to 40 layers) on nearly all substrates under investigation (Ag(111). Ag(l00), Cu(100), Cu(111)). The Cls and Nls NEXAFS spectra of these condensed layers show several very sharp resonances. The comparison with the quinoide molecules TCNQ and DMe-BQ shows similarities, but the electronic structure is too complicated to be interpreted m terms of a building block scheme. NEXAFS data of related charge transfer salts consist of fewer and much broader resonances in accordance with the more delocalized electronic structure of the 'quasimetaUie' salts.
© EDP Sciences 1997