Inducing an antiferroelectric phase by segregating the layers of an intrinsically ferroelectric phase-only liquid crystal with linear-shaped molecules

Abstract

This paper demonstrates the possibility of inducing an antiferroelectric phase from an intrinsically ferroelectric phase-only liquid crystal by doping with linear-shaped molecules, thus separating the neighboring smectic layers of the ferroelectric liquid crystal from each other. Such an intrinsically impossible process is, in fact, shown to be quite possible due to its entropy-related origin. When the temperature of the doped cell is increased, the antiferroelectric phase reverts to the ferroelectric phase as the dopant molecules change position from interlayer space to intralayer space, a result that coincides with the sawtooth model suggested by Glaser and Clark [Phys. Rev. E 66, 021711 (2002)]. The macroscopic spontaneous polarization of the induced antiferroelectric phase (13.5nC∕cm2) is smaller than that of the ferroelectric phase (73.3nC∕cm2), which shows that the charge fluctuation is not the origin of the conversion.