Regensburg 2004 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.70: Poster

Donnerstag, 11. März 2004, 16:00–18:00, Poster D

Comparison of Three-dimensional Simulations of Dendrites with Experimentally Grown 3D Xenon Crystals — •Herman M. Singer and Jörg H. Bilgram — Laboratorium für Festkörperphysik, ETH Zürich, 8093 Zürich (Schweiz)

Dendritic growth from a pure substance into supercooled melt was simulated in two- and three-dimensional calculations of two different phase field models ([A.A. Wheeler, B.T. Murray and R.J. Schaefer, Physica D 66, 243 (1993)] and [A. Karma and W.-J. Rappel, Phys. Rev. E 57, 4323 (1998)]). By means of large scale parallel molecular dynamics simulations for a Lennard-Jones potential, estimates for the anisotropy of interfacial free energy for our experimental model substance were calculated. In our in situ experiments three dimensional xenon crystals during free growth can be observed. Apart from dendrites, doublon and seaweed morphologies as well as morphology transitions are observed. Those structures can be simulated by using special initial conditions. A morphology diagram for 2D and 3D simulations is presented and compared with the results of experiments and analytical studies.