FREE-GROWTH PROPERTIES OF A NEMATIC-SMECTIC-B LIQUID-CRYSTAL INTERFACE

Three types of smectic-B (Sm-B) germs with respect to the director orientation inside and outside the germ have been found. Two of them are planar and one is homeotropic. The equilibrium shapes have been recorded and the angle dependence of the surface tension has been determined by Wulff construction. The planar germs undergo a dramatic change of morphology as a function of undercooling, starting from an elongated, rectanglelike shape to dendritic growth of fourfold symmetry. Near equilibrium the homeotropic germs have a circular form with a small hexagonal modulation, and show a dense branching morphology for larger undercoolings. Growth rates have been measured and compared for all types of germs in a wide range of undercooling. © 1995 The American Physical Society.