ON INPLANE SMECTIC LAYER REORIENTATION IN FERROELECTRIC LIQUID-CRYSTAL CELLS

We report the results of a systematic investigation of the process of smectic layer reorientation of a ferroelectric liquid crystal on the a pplication of asymmetric electric fields. In contrast to previous repo rts, we observed a reversible smectic layer rotation in the plane of t he substrate, limited by the amount of the director tilt angle, partic ularly also for asymmetric rectangular waveforms. We discuss the behav iour of a variation of external parameters, such as field asymmetry, e lectric field amplitude, frequency, cell gap and temperature in terms of the dominant influences of liquid crystal substrate interactions, d irector switching including the electroclinic effect and electro-conve ctive effects which provides a qualitative description of the smectic layer rotation.