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.