Successive phase transitions in antiferroelectric liquid crystal 4-(1-methylheptyloxycarbonyl)phenyl 4'-octylcarbonyloxybiphenyl-4-carboxylate (MHPOCBC)

• Published in: Japanese Journal of Applied Physics Vol. 30; no. 9A; pp. L1573 - L1575
• Main Authors: ISOZAKI, T, SUZUKI, Y, KAWAMURA, I, MORI, K, YAMAMOTO, N, YAMADA, Y, ORIHARA, H, ISHIBASHI, Y
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01.09.1991
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Physics; Ferroelectric transition; Differential scanning calorimetry; Electrooptical properties; Smectic smectic transformation; Antiferroelectric materials; Chiral compound; Experimental study; Permittivity; Liquid crystals; Organic compounds; Dielectric relaxation
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/jjap.30.l1573

A new antiferroelectric liquid crystal (AFLC), 4-(1-methylheptyloxycarbonyl)phenyl 4'-octylcarbonyloxybiphenyl-4-carboxylate (MHPOCBC), was synthesized and an unidentified phase (designated as SmC x ) was observed between the paraelectric SmA phase and the antiferroelectric SmC A * phase by means of thermal, dielectric and electrooptical measurements. Thermal and dielectric studies suggest that the SmA-SmC x phase transition is of the second order and the SmC x -SmC A * phase transition is of the first order. Two types of electrooptical responses were observed in the SmC x phase: at relatively high temperatures the tristable switching appeared and at low temperatures tetrastables switching was noted. These features are discussed in terms of field-induced transitions.