Characterization of Collective Relaxation Modes of a Ferroelectric Mixture Through Dielectric Spectroscopy

Abstract

Molecular motion of a ferroelectric mixture has been studied by the dielectric spectroscopy in the frequency range of 1 Hz to 35 MHz in different mesophases viz. chiral nematic (N*), ferroelectric (SmC*) and hexatic (SmI*) phases. One soft like relaxation process in the N* phase and usual Goldstone mode in the SmC* phase have been found. A new mode has been detected at ∼50 Hz in the vicinity of SmC*- SmI* phase transition. The dielectric strength of this mode is highly temperature dependent and increases as temperature decreases. Two modes in different frequency ranges (kHz and few hundred Hz ranges) have been detected in the SmI* phase.

Keywords:

• Bond orientation order
• goldstone mode
• hexatic phase
• soft mode

Acknowledgment

One of us (A. D.) is thankful to CSIR (New Delhi) for granting a senior research fellowship.