Spontaneous breaking of minimal surface condition: Labyrinths in free standing smectic films

Damian Pociecha ,Ewa Gorecka ,Nataša Vaupotič ,Mojca Čepic ,Jozef Mieczkowski

Department of Chemistry, Warsaw University
Jozef Stefan Institute

Due to the surface tension liquids tend to minimize the surface area. The minimal surface condition applies also to the freely suspended films made of liquid crystals and as a result the islands and/or deeps that are formed during the drawing of the film are metastable and annealing of the film makes it uniform in thickness. However, in thin free standing films made of dimeric molecules in the smectic phase the minimal surface area condition may be broken and the film surface area suddenly starts to increase, upon lowering the temperature. The periodic modulation of the film thickness is obtained and in result the most fascinating labyrinth structure of crests and valleys is formed.

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