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DS: Fachverband Dünne Schichten

DS 38: Layer Properties: Electrical, Optical and Mechanical Properties

DS 38.1: Vortrag

Donnerstag, 25. März 2010, 14:00–14:15, H8

Modification of coherent acoustic phonon lifetimes in thin gold films by self-assembled monolayers — •Mike Hettich¹, Axel Bruchhausen¹, Oliver Ristow¹, Daniel Issenmann¹, Tobias Geldhauser¹, Ingo Wenke², Jürg Bryner², Jürg Dual², and Thomas Dekorsy¹ — ¹Department of Physics and Center of Applied Photonics, Universität Konstanz, Germany. — ²Institute for Mechanical Systems, ETH Zürich, Switzerland.

The damping of coherent acoustic phonons in thin gold films has been investigated by asynchronous optical sampling (ASOPS)[1].

In order to measure the damping constants for various frequencies gold films are grown in a wedge shape. Different film thicknesses correspond to changes in the phonon oscillation frequencies which can therefore be measured by scanning over the sample surface.

For lower frequency phonons in the range of 50 GHz to ∼ 75 GHz a significant change in damping times is observed when a self assembled monolayer is added between the gold film and the substrate. The damping behaviour with and without self-assembled monolayer has been modelled with good agreement by a visco-elastic simulation.

[1] A. Bartels et al., Rev. Sci. Instr. 78, 035107 (2007).