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DY: Fachverband Dynamik und Statistische Physik
DY 16: Pattern Formation
DY 16.4: Talk
Wednesday, March 13, 2013, 10:30–10:45, H46
Crystal Growth in a Channel: From Merry-Go-Round Fingers to Seesaw Dynamics — •Klaus Kassner1, Jean-Marc Debierre2, and Rahma Guerin2 — 1Otto-von-Guericke-Universität, Magdeburg — 2Institut Matériaux Microélectronique Nanosciences de Provence, Marseille
We study three-dimensional solidification in capillaries of various cross sections (triangular, square, hexagonal, circular) by numerical simulation, using Karma’s phase-field model. Besides symmetric and asymmetric steady states expected from acquaintance with the 2D case, we find a number of hitherto unknown dynamical states, some of which were quite unexpected. In particular, there is chiral symmetry breaking leading to rotation of a growing nanocrystal in a hexagonal or circular channel. This seems to be the simplest system so far in which spontaneous breaking of chiral symmetry has been observed. A general characterization of oscillatory states (including movies) and bifurcation diagrams in terms of the undercooling and system size will be given. Some chaotic states have also been observed.