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O: Oberflächenphysik

O 28: Postersitzung (Elektronische Struktur, Grenzfläche fest-flüssig, Halbleiteroberflächen und -grenzflächen, Magnetismus und Symposium SYXM, Methodisches, Nanostrukturen, Oberflächenreaktionen, Teilchen und Cluster, Zeitaufgelöste Spektroskopie)

O 28.49: Poster

Mittwoch, 10. März 2004, 16:00–19:00, Bereich C

Generation of metal nanodroplets and experiments on their velocity and landing — •Anja Habenicht, Michael Olapinski, Johannes Boneberg, and Paul Leiderer — Universität Konstanz, FB Physik SFB 513, 78457 Konstanz

An interesting observation can be made when gold nanostructures placed on a substrate are illuminated with an intensive short laser pulse: Just above the melting threshold all particles leave the surface. The reason for this effect is the wetting behaviour: Gold does not wet the glass substrate, thus the liquid nanostructures can reduce their surface energy by reforming to spheres. If this transformation is sufficiently fast the liquid spheres take off from the surface. The velocity of the flying nanodroplets can be determined by analyzing the time dependent scattering signal which arises when the droplets cross a sheet of light. This signal can be converted into a velocity dependent particle density. The particles cool down during the flight due to thermal radiation. By catching the nanodroplets on a further substrate at different distances, the droplets can be landed either in liquid or in solid state. First results of velocity measurements and the impact experiments are shown.