title: Size dependence of L2,3 branching ratio and 2p core-hole screening in x-ray absorption of metal clusters.
abstract: Resonant 2p x-ray absorption spectra of size-selected transition metal ions and clusters consisting of 1<or=n<or=200 atoms are reported. Remnants of atomic multiplet splitting in L(2,3)-edge x-ray absorption can be resolved up to the trimer, above which the overall line shape is already bulklike. A strong cluster size dependence of the L(2,3) branching ratio was found for titanium, vanadium, and cobalt clusters. While 3d electron delocalization increases with cluster size, the apparent 2p spin-orbit splitting remains constant within the error bars. The size dependence of the L(2,3) branching ratio can be attributed to cluster size specific screening of the 2p-3d Coulomb interaction by 3d/4s valence electrons.
authors.affiliation: Institut für Optik und Atomare Physik, EW 3-1, Technische Universität Berlin, Hardenbergstrasse 36, D-10623 Berlin, Germany. tobias.lau@physik.tu-berlin.de
authors.forename: J T
authors.initials: JT
authors.lastname: Lau
authors.forename: J
authors.initials: J
authors.lastname: Rittmann
authors.forename: V
authors.initials: V
authors.lastname: Zamudio-Bayer
authors.forename: M
authors.initials: M
authors.lastname: Vogel
authors.forename: K
authors.initials: K
authors.lastname: Hirsch
authors.forename: Ph
authors.initials: P
authors.lastname: Klar
authors.forename: F
authors.initials: F
authors.lastname: Lofink
authors.forename: T
authors.initials: T
authors.lastname: Möller
authors.forename: B
authors.initials: B
authors.lastname: v Issendorff