Bragg-microscopic experiments on solidifying colloidal melts

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Two applications are discussed in some detail. First we observe the quasi-homoepitactic growth kinetics of oriented, monolithic but highly twinned body centred cubic crystals to obey a Wilson-Frenkel growth law above the melting line. Below, i.e. in coexistence, we observe a different growth mechanism giving rise to non-linear advancement of the crystal-melt interface as a function of time. Secondly, we investigate the coarsening behaviour of the mentioned twin domains and observe kinetics compatible with Lifschitz-Allen-Cahn behaviour. Lateral coarsening, however, ceases above a critical crystal height, and a columnar morphology results. Further applications and the limitations of the method are discussed.

M. R. Maaroufi, A. Stipp, Th. Preis, Th. Palberg
Inst. f. Physik, Johannes Gutenberg-Universität, Mainz
Scientific and Technical Information
Edition CDR 5, pp. 35-51
December 2001