LENGTH SCALE DEPENDENCE OF CHIRAL-SYMMETRY BREAKING IN FREESTANDING FILMS OF ACHIRAL SMECTIC-C

The textures of a smectic C phase in free-standing films of the Schiff base 50.6 are studied as a function of the number of layers and tempe rature. Periodic stripes with alternating contrast are observed in SmA boundary layers. On further cooling a transition to the splay stripes occurs in the smectic A temperature interval. In the smectic C phase all the periodic textures disappear, whereas in films with one free bo undary a periodic arrangement of splay stripes is found. Mechanisms of symmetry breaking are discussed. (C) 1996 American Institute of Physi cs.