Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 12: Nanostructures at Surfaces II (Wires, Tubes)
O 12.6: Vortrag
Montag, 26. März 2007, 15:30–15:45, H36
Surface enhancend infrared absorption (SEIRA) on single gold nanowires — •Frank Neubrech1, Gerhard Fahsold1, Thomas Cornelius2, Shafqat Karim2, Javier Aizpurua3, Reinhard Neumann2, and Annemarie Pucci1 — 1Kirchhoff-Institut für Physik, Universität Heidelberg — 2Gesellschaft für Schwerionenforschung, Darmstadt — 3Donostia International Physics Center, San Sebastian
We perform surface enhanced infrared (IR) absorption of adsorbates on single gold nanowires using synchrotron light at the ANKA beamline (Forschungszentrum Karlsruhe). The examined nanowires with diameter of about 100nm are prepared by electrochemical deposition in polymeric etched ion track membranes and transferred onto infrared-transparent substrates (e.g. ZnS, CaF2). Performing spectroscopic IR-microscopy we observed antenna-like plasmon resonances for a few micrometer long nanowires. For a demonstration of SEIRA on single gold nanowires we used an octadecanthiol (ODT) monolayer as adsorbate. For wires with resonances in the 3 µm range we observe significant absorption bands at 2850 cm−1 and 2919 cm−1, corresponding to the CH stretching vibrations of ODT. In the case of gold wires with antenna resonance at much higher resonance wavelength CH stretching vibrations could not be observed. The appearance of the absorptions bands is interpreted as an indication of local field enhancement due to the presence of the nanowire.