Dresden 2011 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 5: Photoionization I
A 5.3: Vortrag
Montag, 14. März 2011, 15:00–15:15, BAR 106
X-ray Photoelectron Spectroscopy of Free Silicon Dioxide Nanoparticles near the Si 2p Absorption Edge — •Egill Antonsson1, Burkhard Langer1, Johan Söderström2, Christophe Nicolas2, Olivier Sublemontier3, Xiojing Liu2, Christina Graf1, Peter Schmiel1, Ghassen Saidani4, Jean-Luc Le Garrec4, Emmanuel Robert2, James Brian Mitchell4, Paul Morin2, Cécile Reynaud3, Catalin Miron2, and Eckart Rühl1 — 1Institut für Chemie und Biochemie, Freie Universität Berlin, Germany — 2Synchrotron SOLEIL, Gif-sur-Yvette, France — 3Laboratoire Francis Perrin, Gif-sur-Yvette, France — 4University of Rennes, Rennes, France
The physical and chemical properties of nanoparticles are a subject of great interest. Their unique properties are often related to their high surface-to-bulk ratio. In order to study the intrinsic properties of nanoparticles free from interactions with any surrounding medium, we have used aerodynamic focusing to form a beam of nanoparticles in high vacuum. We have studied the photoemission from silicon dioxide nanoparticles (diameter: 50-200 nm) after excitation near the Si 2p absorption edge over a wide electron-kinetic-energy range. This reveals contributions from direct photoelectrons, Auger electrons, inelastically scattered electrons, and Auger electron channels as well as slow secondary electrons. Specific attention is given to electron-electron coincidence events involving emission of two electrons. The emission of two secondary electrons is the most common process involving emission of two electrons.