Berlin 2005 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 24: Teilchen und Cluster I

O 24.7: Vortrag

Samstag, 5. März 2005, 16:30–16:45, TU EB301

Silver Nanowires — •Dieter Wagner¹, Andreas Graff², Harald Ditlbacher³, and Uwe Kreibig¹ — ¹I. Physikalisches Institut 1A, RWTH Aachen, 52056 Aachen — ²MPI für Mikrostrukturphysik, 06120 Halle — ³Karl-Franzens-Universität Graz/Austria

Free silver nanowires were produced in an aqueous electrolyte by a novel chemical reaction. The diameters are about 27 nm, the lengths range up to more than 70 µm. (!) Their structure was found by TEM analysis (SAED) and HRTEM to consist of five monocrystalline rods of triangular cross section. [1]

Here we present the results of two optical experiments on these nanowires. In the first experiment the polarisation dependency of scattered visible light of one single wire in the spectral region of the plasmon resonance was confirmed by using Zsigmondy darkfield microscopy. Only if the incident electrical field has a component perpendicular to the wire axis, a spectrally selective plasmon polariton is excited. By the second experiment the applicability of the wires as plasmon wave guides was demonstrated. Exciting the plasmon polariton locally at one tip of the wire the decrease of its intensity along the wire axis could be registrated by nearfield fluorescence exitation of a dye embedded in the surrounding PMMA medium. As a result, the propagation length is larger than 10 µm.

[1] A. Graff, D. Wagner , H. Ditlbacher and U. Kreibig, Silver Nanowires, European Physical Journal (EPJ) D, to appear.