Delayed response of the alkyl chains during dynamical switching in a chiral, antiferroelectric liquid crystal probed by dynamic and polarized infrared spectroscopy

We report a time-dependent response of different molecular segments during dynamical switching in the electric-field-induced ferroelectric phase of a chiral, smectic antiferroelectric liquid crystal. From measurements of temporal response of absorption changes of infrared bands over a range of polarizer orientations at different time delays, we demonstrate that the cores respond instantaneously on switching the electric field, while the chiral and achiral alkyl chains require an induction period of {~}15 {μ}s before responding to the electric field. Our studies also reveal that the alkyl chains are less tilted with respect to the layer normal than the cores and reach their equilibrium orientation later than the cores during switching.