Hexatic and blue phases in a chiral liquid crystal: optical polarizing microscopy, synchrotron radiation and dielectric study

Phase behavior, structure and molecular dynamics of a chiral liquid crystalline compound, which exhibits SmG*, SmJ*, SmF*, SmI*, SmC*, SmA*, N* and BP*, have been investigated. Observed optical textures, synchrotron radiation diffraction data and frequency dependent dielectric spectroscopic study clearly depict the temperature evolution of the different hexatic smectic phases along with cholesteric and blue phase in a single compound. In hexatic phases dielectric absorption spectra show one low frequency relaxation process, related to the phase fluctuation of the bond orientational order, and one high frequency process related to amplitude fluctuation of the bond orientational order coupled with the polarization and tilt of the molecules. Goldstone and soft mode relaxation processes are detected, respectively, in SmC* and SmA* phases. (paper)