Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MM: Metall- und Materialphysik

MM 25: Poster Session

MM 25.16: Poster

Mittwoch, 29. März 2006, 15:30–17:30, P4

Characterization of Instabilities of 3D Xenon Crystals — •Oliver Wittwer and Jörg Bilgram — Laboratorium für Festkörperphysik, ETH, CH 8093 Zürich, Switzerland

The formation of complex structures like dendrites and seaweed is an example of structure formation at conditions far from equilibrium. We use xenon as a model substance in our experiments to study the growth of three dimensional crystals.

Instabilities of the solid-liquid interface are responsible for the formation of sidebranches as well as for tip splitting and the formation of multiple tips. The formation of doublons and multiple tips can be initiated in our experiments by changing the temperature distribution around the dendrite tip [1].

We report on transitions from dendrites to doublons, triplons and quadruplons. A symmetry classification of these structures has been developed. We have found a new type of doublon with different symmety. Examples and a characterization of such transitions will be presented.

[1] I. Stalder and J. H. Bilgram, Europhys. Lett. 56, 829 (2001)