Topological defects in smectic islands in freely suspended films

Abstract

Textures created by point topological defects in defects in polar smectic films have been studied. Such defects have been created by the dynamic method (substance from a very thin film does not have time to approach its edges and thicker islands with a topological defect are controllably formed). Topological defects have been studied in smectic islands with a thickness of six to eight molecular layers in a film with a thickness of two molecular layers. Competition between two-dimensional orientational elasticity in islands and the orientation of the director at the boundary of smectic islands results in different configurations of the field of the c-director created by a topological defect. A transition between configurations occurs at a change in the dimension of islands and depends on the dipole polarization of a liquid crystal. The comparison of the numerical calculations of the structure of topological defects with experimental data has allowed determining the dependence of the anisotropy of the two-dimensional orientational elasticity on the polarization of smectic films.