BROAD-BAND DIELECTRIC-RELAXATION STUDY IN A FERROELECTRIC LIQUID-CRYSTAL BY TIME DOMAIN REFLECTOMETRY

Complex permittivity of a ferroelectric liquid crystal, 4-[(S, S)-2, 3-epoxyhexyloxy]-phenyl 4-(decyloxy)-benzoate, has been measured in the frequency range between 10MHz and 4GHz, at temperatures from 112 C down to 53°C by using a time domain reflectometry. Spectral decomposition of the experimental data showed that two types of relaxation are involved. The faster relaxations are active in the ferroelectric phase whereas the slower ones are very much hindered. It can be concluded that this hindered relaxation may correspond to the slowing down of the molecular motion around the long axis, which has been considered as leading to a resultant macroscopic polarization. © 1991, Taylor & Francis Group, LLC. All rights reserved.