Electro-optic study of antiferroelectric freely suspended films of bent-core mesogens in the B2 phase.

We report the electro-optic investigation of a liquid crystalline free standing film formed by bent-core (banana-shaped) mesogens. The ground state of the B2 phase in the films is chiral and antiferroelectric, although the mesogenic molecules themselves lack chirality. The films can be switched in lateral electric fields. In the antiferroelectric ground state, the external electric field in the film plane couples to a small residual spontaneous polarization which we attribute to the incomplete compensation of polarizations of neighboring smectic layers, due to a nonzero twist normal to the layers. We derive viscoelastic parameters from the uniform switching dynamics and the structure of domain walls. Dynamic patterns in rotating fields are observed and analyzed.