Temperature Dependence of Dielectric Behaviour of MHPB(H)PBC Antiferroelectric Liquid Crystal.

Temperature dependence of dielectric behavior of antiferroelectric liquid crystal, MHPB(H)PBC, has been investigated in the frequency range of 1  Hz to 10  MHz. The experimental results have been analyzed using a generalized Cole–Cole expression. There is mainly one relaxation mechanism in SmA∗ phase, which behaves as soft mode. Two dielectric relaxation processes have been observed in SmCA∗ phase, one at about 50  kHz and the other at about 400  kHz. Dielectric strengths of both modes remain constant throughout the SmCA∗ phase, while relaxation frequencies of both modes decrease with decrease in temperature. These two observed modes have been assigned to the in-phase and antiphase azimuthal fluctuations of the director of molecules in the antitilt pairs. [ABSTRACT FROM AUTHOR]