THRESHOLDLESS SWITCHING IN HOMOGENEOUS CELLS AND ANTIFERROELECTRIC CONOSCOPIC FIGURES IN FREESTANDING FILMS AS OBSERVED IN A BINARY SC-ASTERISK-LIKE MIXTURE

To elucidate the V-shaped switching reported by Inui Et al., we have s tudied another binary mixture. In its free-standing film, several subp hases were observed in the ordinary sequence, indicating frustration b etween ferro-and antiferro-electricity; in particular, the antiferroel ectric subphase exists in a temperature range as wide as 22 degrees C and the helical pitch is longer than 2.5 mu m. In a homogeneous cell, however, only two liquid crystal phases were distinguished; one is SA and the other is a phase characterized by the nearly V-shaped switchin g. We have concluded that the substrate interfaces induce tilting rand omization, breaking the reduced intrinsic tilting correlation in adjac ent layers.