Studies on the dielectric behavior of ferroelectric liquid crystal material having a TGBA phase

Abstract

Results reported on the studies of electro-optical and dielectric properties of two isomeric and one lower homologue of ferroelectric liquid crystal materials having TGBA phase. Complex dielectric permittivities have been measured in planar aligned cells in the frequency range 10Hz to 10MHz. Bias dependent measurement have been performed in S_C* and TGBA phases. Three different collective modes — Goldstone mode, soft mode and domain mode have been observed in S_C* phase and soft mode is observed in S_Aand TGBA phases. The results of the bias dependent dielectric measurements showed that the bias induced alignment in TGBA phase once achieved is retained even after removal of bias field. The results have been discussed.

Keywords:

• Ferroelectric liquid crystals
• dielectric relaxation Spectroscopy
• twist grain boundary phases
• Goldstone mode
• soft mode
• domain mode