Tristable Switching in Surface Stabilized Ferroelectric Liquid Crystals with a Large Spontaneous Polarization

Abstract

A new switching process was observed in surface stabilized ferroelectric liquid crystals. The switching is associated with a third stable state in addition to the well-known bistable states. The appearance of the third state is characteristic of materials with a large spontaneous polarization and is caused by minimizing induced polarization charges. The switching between each bistable state and the third state exhibits a sharp dc-threshold and hysteresis, suggesting a possible application for a switching device.

On the coexistence of SmC* and SmCA* phases in binary chiral-dopant antiferroelectric mixtures

“…Mesomorphic properties The materials chosen as hosts were (R/S)-8F1M6, (R/S)-10F1M7, and (R/S)-10F2E7 (FIGURE 1), which range from strongly synclinic to strongly anticlinic. The dopants used were 10% (S)-IGS97 [10] and 15% (S)-MHPOBC [11] (by weight). The first is a standard non liquidcrystalline ("ferroelectric-like") dopant used in chiral-dopant FLC mixtures and strongly promotes the SmC* phase, and the latter strongly promotes the SmC A * phase.…”

Chiral Liquid Crystals: Structures, Phases, Effects

“…Having demonstrated the occurrence of a spontaneous polarization and the property of ferroelectricity for the chiral, tilted SmC* phase, it should be noted that also other similarities to solid state materials can be observed, namely antiferroelectric [97][98][99] and intermediate [100,101] structures. Just like their ferroelectric counterpart, the former exhibit a helical superstructure, which for now we neglect for reasons of clarity.…”

Optics and electrooptics of chiral smectic C liquid crystals

“…В заключение отметим, что в некоторых работах, появившихся в последнее время, отмечен ряд новых особенностей электрооптических свойств С*ЖК, ко торые не укладываются в упомянутые выше пред ставления: это, например, появление третьего ста бильного состояния в поверхностно стабилизиро ванных структурах, обладающих высокой спонтан ной поляризацией (~ 100 НК/см ) [126], переклю чение, связанное с движением дисклинаций между твистовыми состояниями [127] и т.д.…”