Paraelectric-antiferroelectric phase transition in achiral liquid crystals.
Critical freezing of molecular rotation in an achiral smectic phase, which leads to polar ordering through the second order paraelectric-antiferroelectric (Sm-A-->Sm-APA) phase transition is studied theoretically and experimentally. Strong softening of the polar mode in the Sm-A phase and highly intensive dielectric mode in the Sm-APA phase are observed due to weak antiferroelectric interactions in the system. In the Sm-APA phase the dielectric response behaves critically upon biasing by a dc electric field. Such a behavior is found general for the antiferroelectric smectic phase with significant quadrupolar interlayer coupling.
Department of Chemistry, Warsaw University, Al. Zwirki i Wigury 101, 02-089 Warsaw, Poland.
Damian
D
Pociecha
Ewa
E
Gorecka
Mojca
M
Cepic
Natasa
N
Vaupotic
Kinga
K
Gomola
Jozef
J
Mieczkowski