Studies of Phase Diagram and Glass Transitions of a Liquid Crystal with Ferro- and Antiferroelectric Phases

Based on the results of the differential scanning calorimetry, of transmitted light intensity measurements and of texture observations the phase diagram of 4-(6-heptafluorobutanoiloxyhexyloxy)biphenyl-4'-carboxylate(S)-4-(methyloheptyloxy-1-carbonyl)-phenyl (4H6) was obtained. The following phases were identified on cooling: isotropic, smectic A, smectic C*, smectic $C_{A}^\ast $ phases and a highly ordered phase called SmX and its glass. During heating transformation from glass of SmX to SmX phase and then transition to a metastable Cr2 phase, evolving to the more stable Cr1 phase, were observed. On further heating $ SmC_{A}^\ast $, SmC* and Sm phases were identified. When Cr2 was cooled, a glass transition was also observed.