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Nanostrukturen und Grenzflächen Poster: Do., 13:00–15:30 D-P294
Electronic Structure of Free and Supported Transition Metal Clusters
Tobias Lau 1 , Vicente Zamudio-Bayer 1 , Leif Glaser 2 , Theresa Schadow 1 ,
Marlene Vogel 1 , Jochen Rittmann 1 , Wilfried Wurth 2 , Bernd von
Issendorff 3 , Thomas Möller 1
1 TU Berlin, IAPF, PN 3-1, Hardenbergstraße 36, 10623 Berlin – 2 Universität Hamburg,
Institut für Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg – 3 Albert-
Ludwigs-Universität Freiburg, Fakultät für Physik, Stefan-Meier Straße 21, 79104
Freiburg
Electron localization and correlation are important factors determining the electronic
structure of 3d transition metals. In free 3d transition metal atoms, Coulomb interaction
of the 2p core hole with the localized 3d electrons leads to multiplet splitting of the
L2,3 absorption lines. In bulk transition metals, valence electrons are partially delocalized.
In addition, multiplet splitting might be masked by line broadening. The issue of
electron localization/delocalization and correlation in the transition from single atoms
to bulk metals can ideally be addressed in the investigation of size-selected transition
metal clusters. So far, however, the 3d multiplet structure in L2,3 X-ray absorption of
deposited small metals clusters has not been observed neither on metal nor on HOPG
substrates. We report here on the first study of the multiplet structure of small, mass
selected chromium and cobalt clusters deposited on thin potassium films as well as on
Cu(100). Potassium films were chosen as substrates, since 3d transition metal impurity
atoms on alkali metal films show highly localized atomic configurations. A preliminary
analysis of the experimental data suggests that the same atomic-like components might
also be visible in small clusters.
In addition to investigations on mass selcted, deposited clusters, first results on X-ray
absorption spectroscopy on free transition metal clusters will be presented.