Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 36: Poster Session II (Organic films and electronics, photoorganics; Nanostructures; Plasmonics and nanooptics, Surface chemical reactions and heterogeneous catalysis, Surface dynamics )
O 36.79: Poster
Dienstag, 12. März 2013, 18:15–21:45, Poster B2
UV-VIS absorption and XANES of Ag clusters in matrices — •Stefanie Duffe1, David Engemann1, Sabrina Hoffmann1, Christian Sternemann1, Ralph Wagner2, Kristina Kvashnina3, Pieter Glatzel3, and Heinz Hövel1 — 1TU Dortmund, Fakultät Physik / DELTA, Dortmund, Germany — 2BU Wuppertal, Fachgruppe Physik-Materialwissenschaften, Wuppertal, Germany — 3ESRF, Grenoble, France
We produce Ag clusters by supersonic nozzle expansion using THECLA, a THErmal CLuster Apparatus [1,2] which was designed to enable optical spectroscopy of clusters in a free jet and deposited on silica glass [2] or in matrices. The optical properties and the UV-VIS absorption band of Ag clusters alter significantly with size, shape, interparticle spacing and the properties of the local environment. Embedding the clusters into polydimethylsiloxane (PDMS) [3], aerogel or ionic liquids enables the investigation of a much higher amount of separated clusters which is otherwise limited by coalescence and electromagnetic coupling. We investigate the plasmon resonance of Ag clusters in PDMS or aerogel by optical spectroscopy [4]. XANES measurements at the Ag L1,2,3-edges [5] were carried out at the synchrotron radiation sources DELTA and ESRF and were compared to FEFF calculations.
[1] O. F. Hagena, Z. Phys. D 20, 425 (1991). [2] H. Hövel et al., Phys. Rev. B 48, 18178 (1993). [3] L. Ravagnan et al., J. Phys. D 42, 082005 (2009). [4] U. Kreibig et al. In: Advances in Metal and Semiconductor Clusters Vol. 4, (ed. M.A. Duncan), JAI press Inc., 345 (1998). [5] P. Behrens et al., Z. anorg. allg. Chem. 625, 111 (1999).