Re-entrant of normal dielectric permittivity-voltage hysteresis due to molecular relaxation in SmC* phase

Dielectric relaxation and polarization reversal process have been investigated of a ferroelectric liquid crystal material ((S)-4-{4-(2-methyloctanoyl) phenyl} phenyl 3-chloro-4-butyloxyphenylcarboxylate) with high spontaneous polarization in confined geometry. In the SmC* phase, presence of low frequency molecular mode has been confirmed by performing experiment with cells of different thicknesses. Polarization reversal process shows the re-entrant of the normal hysteresis behavior at higher frequency in dielectric constant-voltage characteristics due to the induced polarization for the dipolar rotation. This re-entrance behavior can be used to distinguish the absorption peak in the dielectric spectra arising due to the molecular rotation from that of appearing due to the cell relaxation. (c) 2006 Elsevier B.V. All rights reserved.