Huge dielectric constants of the ferroelectric smectic-A phase in bent-shaped dimeric molecules

Abstract

We present the dielectric relaxation properties of the ferroelectric smectic-A (SmAP_F) phase formed by a mixture of bent-shaped dimeric molecules α,ω-bis(4-alkoxyanilinebenzylidene-4′-carbonyloxy)pentanes with different alkyl chain lengths. The SmAP_F phase shows a Goldstone-like mode at approximately 500 Hz, which can be attributed to the ferroelectricity and huge dielectric strength (Δε). Δε varies dramatically with the cell thickness; in particular, it attains more than 7000 in a 50 μm-thick cell, which is much higher compared to that reported in the bent-shaped molecules.