Molecular correlations in a ferroelectric liquid crystal

Measurement of the molecular correlation length of the ferroelectric liquid crystal $S\ensuremath{-}2\mathrm{m}\mathrm{e}\mathrm{t}\mathrm{h}\mathrm{y}\mathrm{l}\mathrm{b}\mathrm{u}\mathrm{t}\mathrm{y}\mathrm{l}\ensuremath{-}4\ensuremath{-}n\ensuremath{-}\mathrm{d}\mathrm{e}\mathrm{c}\mathrm{a}\mathrm{n}\mathrm{o}\mathrm{y}\mathrm{l}\mathrm{o}\mathrm{x}\mathrm{y}\mathrm{b}\mathrm{i}\mathrm{p}\mathrm{h}\mathrm{e}\mathrm{n}\mathrm{y}\mathrm{l}\ensuremath{-}{4}^{\ensuremath{'}}\ensuremath{-}\mathrm{c}\mathrm{a}\mathrm{r}\mathrm{b}\mathrm{o}\mathrm{x}\mathrm{y}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{e}$ (2M4DBC) has been obtained from field-dependent pyroelectric studies. The liquid-crystal behavior can be described in terms of a dynamically fluctuating mixture of two conformers having polarizations of opposite sense. The relative density of these species can be altered with an electric field, thereby allowing measurement of the effective dipole moment and correlation volume of the molecular clusters.