Surface electroclinic effect in a smectic-A liquid crystal

摘要

Polar interactions between liquid crystal molecules and cell surfaces give rise to the surface electroclinic effect. This results in rotation of the layer normal away from the alignment direction near the surface and an interfacial region where the molecular director twists from the alignment direction until it reaches the layer normal direction. We have investigated the molecular orientation within the smectic layer using linear and circular dichroism spectroscopy. Contrary to theoretical predictions, the magnitude of the surface electroclinic tilt is relatively temperature independent, while the bulk electroclinic coefficient strongly depends on temperature.