ELECTRIC-FIELD-INDUCED STRUCTURAL TRANSITIONS IN ANTIFERROELECTRIC LIQUID-CRYSTALS

We have made the first calculations of i) the effect of an electric fi eld on the structures corresponding to different phases exhibited by a ntiferroelectric liquid crystals (using a model proposed by us earlier ), ii) the apparent tilt angle corresponding to these field distorted structures and iii) the conoscopic figures exhibited by such nonunifor mly modulated structures with biaxial layers. The field induces new co mmensurate structures in the antiferroelectric, ferrielectric and SmCa lpha phases, the last one occurring between ferro and para electric p hases. The results compare well with the available experiments, showin g that the different structures predicted by the axial next nearest-ne ighbour xy-model are realistic.