A SIMPLE GEOMETRICAL MODEL FOR THRESHOLD BEHAVIOR AND MOLECULAR SWITCHING DYNAMICS IN ANTIFERROELECTRIC LIQUID-CRYSTALS

We have developed a geometrical model for the field induced antiferroe lectric-ferroelectric (AF-FO) liquid crystal phase transition. The mod el is based on the electrostatic dipolar interactions between two near est neighboring dipoles at the molecular ends. The observed temperatur e dependences of the threshold field, E-th, for the AF-FO transition, the polarization, P, in the FO phase, the molecular switching are cons istent with theoretical predictions. A linear relationship between E-t h and P is found in the region where the molecular tilt remains fairly constant.