Smectic layer reorientation by surface mode in surface stabilized ferroelectric liquid crystal

Abstract

We report the smectic layer reorientation process in a surface-stabilized ferroelectric liquid crystal subject to the surface mode dominance at certain temperature and application of the controlled measuring field strength. The process is investigated by dielectric spectroscopy and optical textures analysis simultaneously in heating and cooling cycle. First the smectic layers are reoriented just 1–2 ^oC below T_c by applying a bias of 0.5 V as the material is soft here and cooled the sample to room temperature in absence of bias field which we call this a treated cell. In second type, the cell was taken to just above the T_c and taken the measurement in cooling cycle which we call an untreated cell. We have observed that there is a distinct molecular dynamic in the heating and cooling cycles of the material due to reoriented smectic layering and surface effect which assists the reorientation. It has also been observed that in heating cycles, the surface effect phenomenon is dominant, and in cooling cycles, it is weaker. Sometimes, the heating and cooling of the sample under electric field has been found affecting the optical performance of sample due to the readjustment of smectic layers. This study may clarify the control over the layer reorientation by surface effect and may open the possible application in displays and optical communication devices.