Frustoelectric phase

Figure 6.3.25 shows the relationship between applied voltage and transmittance of the frustoelectric phase measured by applying a triangular wave electric field. The V-shaped relationship can be observed. Without applied voltage, the optical axis is parallel to the layer normal. 

Fig. 6.3.25 Relationship between applied voltage and transmittance of the frustoelectric phase.

IR absorption anisotropies of the phenyl ring vibration mode at 1605 cm for the SmA phase and the frustoelectric phase without applied voltage show that the molecular ordering in this phase at zero field is almost the same as that in SmA phase. Furthermore, the maxima and minima of the IR absorption anisotropies under the electric field do not change from those at zero field. These phenomena mean that the molecular distribution at zero voltage is the same as that under the electric field. These phenomena including the chevron structure can only be explained by the model shown in Fig. 6.3.28 [46]. 

Among these modes, (2) DHF mode, (3) twisted FLC mode, (4) monostable FLC mode, (8) CDR mode, (5) the application of Parallel Stripe Texture and (9) the application of the frustoelectric liquid crystalline phase are reviewed below. 

The molecular interaction between each lajrer is weak and the molecular directors in one layer are not strongly bound by molecular directors in the adjacent layers. As a result, neither a ferroelectric liquid crystal state nor an antiferroelectric liquid crystal state can be realized in forming this random orientation. In the early stages, these materials were called thresholdless antiferroelectric liquid crystals (TLAF) . However, for these materials antiferroelectric order or antiferroelectricity cannot be observed. Recently, the terms frustoelectricity and frustrated electricity have been proposed [36]. These terms imply that the formation of both ferroelectricity and antiferroelectricity are prohibited and neither phase can be formed. 

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