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Electrooptic and dielectric properties were studied in the antiferroelectric phase, B 2 , 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.

Microscopic polarized fourier-transform infrared (FT-IR) measurements were performed in the antiferroelectric B2 phase of a bent-shaped liquid crystal molecule. In homogeneously chiral domains, the absorbance maximum appeared when the transmission axis of a polarizer was parallel to the layer normal for the phenyl ring stretching and C-0-C asymmetric stretching and that for the C=O stretching was almost perpendicular to that for C-0-C in the absence of a field. When a dc field was applied, the maximum for C-0-C rotated by about 35". which is almost the same as the apparent tilt angle of the molecule. In contrast, the axis of maximum absorbance for C=O was neither parallel nor perpendicular to that of C-0-C under a field. It indicates that the two ester groups are twisted with respect to the central phenyl ring and are not perpendicular to the molecular long axis. Moreover, one of the twist conformations is chosen and the rotation around the molecular long axis is strongly hindered.