title: Evidence for de Vries structure in a smectic-A liquid crystal observed by polarized Raman scattering.
abstract: The second- and fourth-order apparent orientational order parameters of the core part of the molecule P2 (app) and P4 (app) , have been measured by polarized vibrational Raman spectroscopy for a homogeneously aligned ferroelectric smectic liquid crystal with three dimethyl siloxane groups in the achiral terminal chain, which shows de Vries-type phenomena, i.e., very large electroclinic effect in the smectic- A (Sm-A) phase and a negligible layer contraction at the phase transition between the Sm-A and Sm- C(*) phases. The apparent orientational order parameters of the rigid core part of the molecule are extremely small both with and without the external electric field in Sm-A . These results provide evidence for the existence of the de Vries Sm-A phase, where the local molecular director is tilted at a large angle.
authors.affiliation: Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan. naoki_a_hayashi@fujifilm.co.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Hayashi
authors.forename: Tatsuhisa
authors.initials: T
authors.lastname: Kato
authors.forename: Atsuo
authors.initials: A
authors.lastname: Fukuda
authors.forename: Jagdish K
authors.initials: JK
authors.lastname: Vij
authors.forename: Yuri P
authors.initials: YP
authors.lastname: Panarin
authors.forename: J
authors.initials: J
authors.lastname: Naciri
authors.forename: R
authors.initials: R
authors.lastname: Shashidhar
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kawada
authors.forename: Shinya
authors.initials: S
authors.lastname: Kondoh