Ratchet effect in faceting: a growth of perfect lyotropic crystals by temperature cycles.
The paper deals with a new phenomenon, named ratchet effect, envisioned theoretically as a likely consequence of metastability of crystal facets and expected to occur upon a temperature cycling. In experiments, Pn3m lyotropic crystals surrounded by the isotropic L1 phase in the mixture C(12)EO(2)/water are used. At equilibrium, the Pn3m/L1 interface contains small (111)-type facets in coexistence with rough surfaces. In agreement with theoretical expectations, it is shown that upon a saw-tooth-shaped temperature cycling, facets are growing until the rough surfaces are completely eliminated. A model of the ratchet effect is proposed.
Plötzing
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T
Laboratoire de Physique des Solides, Université Paris-Sud, Bât. 510, 91405 Orsay Cedex, France.
Pieranski
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P