Rostock 2019 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 21: Cluster II (joint session A/MO)
A 21.6: Poster
Mittwoch, 13. März 2019, 16:15–18:15, S Fobau Physik
Coulomb interaction in the photoemission of polyanionic silver clusters — •Norman Iwe1, Madlen Müller2, Klara Raspe1, Franklin Martinez1, Steffi Bandelow2, Josef Tiggesbäumker1, Lutz Schweikhard2, and Karl-Heinz Meiwes-Broer1 — 1Institut für Physik, Universität Rostock, Albert-Einstein-Str. 23-24, 18059 Rostock — 2Institut für Physik, Universität Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald
Not only the size but also the charge state is an important parameter of free, nanoscopic particles. In particular the properties of negatively charged metal clusters are strongly influenced by Coulomb interaction between the cluster components. For two and more excess electrons, this results in a Coulomb barrier potential, whose detailed properties are however largely unknown.
This contribution presents photoelectron spectroscopy studies on mass separated silver clusters, after they have been multiply negatively charged in a radiofrequency ion trap. The emitted electron interacts with the still negatively charged cluster which leads to a Coulomb cut-off, as known from molecular anions. To investigate this effect, PE spectra for different photon energies are compared. These spectra are qualitatively described by electrons coming from a Fermi distribution in a Jellium-like potential that either overcome or tunnel through the Coulomb barrier. The project has been supported by the collaborative research center SFB 652 of the DFG.