Ferroelectric liquid crystals: Structure and field induced processes

Abstract

In a planar sample of SmC* liquid crystal helicoidal structure exists in the bulk while the surface layers are unwound. Connection between these two regions is mediated by line defects, 2π disclinations, responsible for the observed line texture. Thin planar samples may be spontaneously unwound and exist in twisted or uniform configurations. Experiments reveal that helix unwinding in an electric field is a more complex process than considered by previous theories. It involves movement of disclinations and their annihilation, reorientation of molecules in the bulk and domain processes in the surface layer. Ferroelectric-like properties of thin samples have application perspectives.