Phase Diagrams of Binary Mixtures of Antiferroelectric and Ferroelectric Compounds with Lactate Units in the Mesogenic Core

• Published in: Ferroelectrics 2004-01, Vol.309 (1), p.103-109
• Main Authors: NOVOTNÁ, V., HAMPLOVÁ, V., KAšPAR, M., GLOGAROVÁ, M., BUBNOV, A., LHOTÁKOVÁ, Y.
• Format: Article
• Language: English
• Subjects: binary mixtures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectric liquid crystals; Ferroelectricity and antiferroelectricity; lactic acid; Materials science; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase transitions and curie point; Physics
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150190490509980

Binary mixtures based on lactic acid derivatives were prepared and studied. Pure compounds differ in the type of linkage of the non-chiral chain to the molecular core, either keto or ether groups, and besides the SmA and SmC* phases they exhibit the antiferroelectric SmC A * or hexatic SmF(I)* phases, respectively. Phases and phase transition temperatures of mixtures were determined. Spontaneous polarization and tilt angle were evaluated in the SmC*, SmC A * and/or SmF(I)* phases. Dielectric spectroscopy has yielded behaviour of modes in vicinity of the phase transition to the antiferroelectric or hexatic phase. The phase diagrams of mixtures show the stability of the hexatic and antiferroelectric phases. These phases become narrower and eventually disappear when concentration of both components approaches to the balance.