Electric-field-induced polar biaxial order in a nontilted smectic phase of an asymmetric bent-core liquid crystal.
A polarization reorientation process has been studied by means of optical second-harmonic generation in an optically uniaxial smectic phase of an asymmetric bent-core liquid crystal. A nontilted polar smectic order with a biaxial order is induced by applying an electric field to the uniaxial nonpolar smectic phase. This phenomenon was well simulated by the two-dimensional Langevin process, i.e., electric-field-induced continuous molecular reorientation against thermal agitation. The simulation suggests that about 200s of molecules form a polar domain and cooperatively respond to the applied field. The existence of the polar domains and their reorientation are consistent to the dielectric measurement; a high dielectric constant of about 60 at the kHz range is markedly suppressed by applying a bias field.
Shimbo
Yoshio
Y
Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
Gorecka
Ewa
E
Pociecha
Damian
D
Araoka
Fumito
F
Goto
Masanao
M
Takanishi
Yoichi
Y
Ishikawa
Ken
K
Mieczkowski
Jozef
J
Gomola
Kinga
K
Takezoe
Hideo
H