Analysis of the Broadening of X-ray Photoelectron Spectroscopy Peaks for Ionic Crystals


  • M.A.B. is grateful to the Alexander-von-Humboldt foundation for a fellowship. We acknowledge support by the Geosciences Research Program, Office of Basic Energy Sciences, U.S. DOE and by the Deutsche Forschungsgemeinschaft through SFB 546 “Transition Metal Oxide Aggregates”, and the “Cluster of Excellence” (UNICAT) administered by the TU Berlin. A portion of the research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.


original image

Breathing: A simple and intuitive approach relates changes in bond lengths of core-hole ionized states to the extent of vibrational fine structure, or Franck–Condon broadening (ΔE), in X-ray photoelectron spectra of ionic compounds. For the extreme case of a monolayer of MgO on Ag(100), the difference in Franck–Condon broadening compared to bulk MgO reflects the different binding situation in the supported oxide (see picture, r=Mg[BOND]O distance).