Ferroelectric-chiral-antiferroelectric-racemic liquid crystal phase transition of bent-shape molecules.
Detailed dielectric, polarization current, electro-optical, and textural observations are reported on an asymmetric banana-shaped compound 1,3-biphenylene-bis[4-(3-fluoro-4-octyloxyphenyliminomethyl)benzoate]. The material possesses a chiral-ferroelectric-racemic-antiferroelectric phase transition. Our studies reveal that the higher temperature ferroelectric phase has a polar double-tilted smectic structure, where both the molecular plane and the long axis are tilted with respect to the layer normal. Accordingly, it has a chiral triclinic structure with an out-of-plane polarization component. The lower temperature phase has a monoclinic symmetry, which is higher than that of the higher temperature phase. To our knowledge, among liquid crystals such situations were previously observed only in reentrant phases.
Rauch
S
S
Techische Universitat Berlin, Stranski-Laboratorium für Physikalische unde Theoretische Chemie, Sekr. ER11, Strasse des 17 Juni 112, 10623 Berlin, Germany.
Bault
P
P
Sawade
H
H
Heppke
G
G
Nair
G G
GG
Jákli
A
A