Dielectric spectroscopy of the twist grain boundary phase and smectic‐like behaviour in the Isotropic Phase

Dielectric properties of a novel liquid crystal with direct transition from isotropic to twist grain boundary (TGB) phase were studied. Measurements were performed over a wide range of temperature in the isotropic phase, TGBA, TGBC and SmC* phases. The Arrhenius plot of the relaxation frequency of the molecular process around the short axis shows a variation in the activation energy in the isotropic phase. This is attributed to smectic‐like fluctuations in the isotropic phase. The dielectric relaxation strength in the TGBC phase has anomalous behaviour in the vicinity of TGBC–SmC* transition. The single cellective process observed in the TGBC phase splits into two processes in the SmC* phase.