Electric-field-induced polar biaxial order in a nontilted smectic phase of an asymmetric bent-core liquid crystal

• Published in: Physical review letters Vol. 97; no. 11; p. 113901
• Main Authors: Shimbo, Yoshio, Gorecka, Ewa, Pociecha, Damian, Araoka, Fumito, Goto, Masanao, Takanishi, Yoichi, Ishikawa, Ken, Mieczkowski, Jozef, Gomola, Kinga, Takezoe, Hideo
• Format: Journal Article
• Language: English
• Published: United States 15-09-2006
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.97.113901

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.