Growth patterns of smectic A liquid crystals

We report observations on the growth patterns of smectic A liquid crystals from the nematic phase in binary mixtures which exhibit an induced smectic phase. In cells prepared with ‘homeotropic’ boundary conditions there is a clear indication of a microphase separation which leads to nucleation of the smectic layers in the centre of the cell, and formation of single focal conic domains. The domains attact each other to form chains which is ascribed to flexoelectric polarization. A high-frequency AC field produces a corrugation of the interface, the spatial period of which decreases rapidly as the field strength is increased. Dust particle motion around the domains indicates that there may be electrohydrodynamic motion in the nematic liquid crystal surrounding the smectic domains.