Electric-Field-Induced Transitions among Antiferroelectric, Ferrielectric and Ferroelectric Phases in a Chiral Smectic MHPOBC

Abstract

A T - E phase diagram of MHPOBC (C 8 H 17 O– - -COO– -COO * CH(CH 3 )C 6 H 13 ) has been obtained by means of the temperature ( T ) dependence of the dielectric constant under a dc biased electric ( E ) field. It is presumed from the T - E phase diagram that there is a temperature range where the field-induced antiferroelectric-ferrielectric-ferroelectric phase transitions take place. These transitions have been confirmed as five transmittance states between crossed Nicols under a triangular wave, i.e., ferro-ferri-antiferro-ferri-ferro. The field-induced antiferroelectric-ferrielectric phase transition has also been identified through conoscopic observation.