Electrooptic and dielectric properties in bent-shaped liquid crystals

Electrooptic and dielectric properties were studied in the antiferroelectric phase, Ba, of bent-shaped liquid crystal molecules. We have succeeded in selectively obtaining the homogeneously chiral domain, the racemic domain, and the intermediate domain in which layers with opposite chirality are partially mixed, by properly choosing particular waveforms of the electric field applied. Tristable switching was observed for all domains under a triangular wave field. The switching current profiles under a rectangular wave field indicate that the switching time of homogeneously chiral domains is slower than that of racemic domains. The magnitude of spontaneous polarization depends not on temperature but on the carbon number of the terminal chain of the molecules. Two relaxation modes were detected in dielectric measurements, one of which was attributed to the distortion of the antiferroelectric ordering.