Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 29: Poster session II (Nanostructures, Magnetism, Particles and clusters, Scanning probe techniques, Time-resolved spectroscopy, Structure and dynamics, Semiconductor surfaces and interfaces, Oxides and insulators, Solid-liquid interfaces)

O 29.29: Poster

Mittwoch, 29. März 2006, 14:30–17:30, P2

Femtosecond Pump-Probe Measurements of Silver Nano-Clusters on Quartz (0001) — •Alexander Grujic, Konrad von Volkmann, and Martin Wolf — Fachbereich Physik der Freien Universität Berlin, Arnimallee 14, 14195 Berlin

We have measured the energy relaxation of supported silver nano-clusters by time resolved transient absorption spectroscopy. The clusters are prepared in UHV via Volmer-Weber growth by evaporation of silver on a single crystal quartz (0001) sample at room temperature, resulting in a mean cluster size of ≈ 12 nm. The sample was excited by 400-nm pump pulses with 40-fs duration, and the transmission was probed with a beam of the same wavelength. In-situ temperature, size and fluence dependent transmission measurements have been performed and a fast (≈ 2…3 ps) and a slow (≈ 150 ps) decay channel have been identified. They are attributed to the electron-phonon relaxation within the silver cluster and the much slower heat transfer of the cluster lattice to the quartz substrate.