Induced antiferroelectric smectic-CA* phase by doping ferroelectric-C* phase with bent-shaped molecules

Doping of the ferroelectric Sm-C* phase with bent-shaped molecules induces the antiferroelectric Sm-C-A* phase. The effect was observed by means of electro-optic and dielectric measurements in systems with weak interlayer interactions in which the relative strength of anticlinic-synclinic order between molecules in adjacent layers is easily controlled by external factors. Fourier-transform infrared spectroscopy studies suggest that the bent-shaped molecules are not flat. They reorient upon the electric field-induced antiferroelectric-ferroelectric transition to adopt a position in which the average direction of the carbonyl groups is in the smectic plane and a bending tip along the C-2 symmetry axis.