ELECTRIC-FIELD-INDUCED LAYER REORIENTATION IN FERROELECTRIC LIQUID-CRYSTALS - AN X-RAY STUDY

We use x-ray diffraction on aligned samples of the smectic-A and -C* phases to confirm the existence of a chevron-layer structure even within the smectic-A phase. Furthermore, we demonstrate that an ac electric field can be used to eliminate the chevron structure and produce uniform orientation of the smectic-C* layers perpendicular to the glass plates. The results of the x-ray study are in agreement with earlier optical observations. The practical implication of the chevron removal is the significant enhancement of the optical contrast of the cell.