Licentiate Thesis: Bonding and Desorption Mechanisms of CO on Metal Surfaces
Friday 01 June 2012
to 12:00 at
Jörgen Gladh (Stockholm University, Department of Physics)
I have investigated two different systems CO/Fe(100) and CO/Ru(0001), to obtain new
information on the binding and desorption processes. The two different systems have served
as a model system, one for a static examination, CO on iron, and for the dynamic case, CO on
ruthenium. To perform these investigations, several types of techniques have been used such
as, X-ray absorption spectroscopy, X-ray emission spectroscopy, and femtosecond laser
induced desorption techniques such as two-pulse correlation.
For the CO/Fe(100) system, we found that the on-top CO “α1 phase” can be described by the
Blyholder-Nilsson-Pettersson model. The pre-dissociative phase of CO bound at hollow sites,
“α3 phase”, can be described in a Dewar-Chatt-Duncanson like picture.
For the CO/Ru(0001) system, it was found that all our data could be fitted from an empirical
friction heat bath model. Moreover, it turned out, that there is a strong frictional coupling to
the substrate electrons and phonons.