title: Orientational ordering in the chiral smectic-C*FI2 liquid crystal phase determined by resonant polarized x-ray diffraction.
abstract: High-resolution resonant polarized x-ray diffraction experiments near the sulfur K edge have been performed on free-standing liquid crystal films exhibiting the chiral smectic-C*FI2 phase. It is widely accepted that this phase has a four-layer repeat unit, but the internal structure of the repeat unit remains controversial. We report different resolved features of the resonant x-ray diffraction peaks associated with the smectic-C*FI2 phase that unambiguously demonstrate that the four-layer repeat unit is locally biaxial about the layer normal and that the measured angle, describing the biaxiality, is in good agreement with optical measurements.
authors.affiliation: School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: A
authors.initials: A
authors.lastname: Cady
authors.forename: J A
authors.initials: JA
authors.lastname: Pitney
authors.forename: R
authors.initials: R
authors.lastname: Pindak
authors.forename: L S
authors.initials: LS
authors.lastname: Matkin
authors.forename: S J
authors.initials: SJ
authors.lastname: Watson
authors.forename: H F
authors.initials: HF
authors.lastname: Gleeson
authors.forename: P
authors.initials: P
authors.lastname: Cluzeau
authors.forename: P
authors.initials: P
authors.lastname: Barois
authors.forename: A M
authors.initials: AM
authors.lastname: Levelut
authors.forename: W
authors.initials: W
authors.lastname: Caliebe
authors.forename: J W
authors.initials: JW
authors.lastname: Goodby
authors.forename: M
authors.initials: M
authors.lastname: Hird
authors.forename: C C
authors.initials: CC
authors.lastname: Huang