title: Resonant x-ray scattering study of the antiferroelectric and ferrielectric phases in liquid crystal devices.
abstract: Resonant x-ray scattering has been used to investigate the interlayer ordering of the antiferroelectric and ferrielectric smectic C* subphases in a device geometry. The liquid crystalline materials studied contain a selenium atom and the experiments were carried out at the selenium K edge allowing x-ray transmission through glass. The resonant scattering peaks associated with the antiferroelectric phase were observed in two devices containing different materials. It was observed that the electric-field-induced antiferroelectric to ferroelectric transition coincides with the chevron to bookshelf transition in one of the devices. Observation of the splitting of the antiferroelectric resonant peaks as a function of applied field also confirmed that no helical unwinding occurs at fields lower than the chevron to bookshelf threshold. Resonant features associated with the four-layer ferrielectric liquid crystal phase were observed in a device geometry. Monitoring the electric field dependence of these ferrielectric resonant peaks showed that the chevron to bookshelf transition occurs at a lower applied field than the ferrielectric to ferroelectric switching transition.
authors.affiliation: Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
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: R
authors.initials: R
authors.lastname: Pindak
authors.forename: J
authors.initials: J
authors.lastname: Pitney
authors.forename: P M
authors.initials: PM
authors.lastname: Johnson
authors.forename: C C
authors.initials: CC
authors.lastname: Huang
authors.forename: P
authors.initials: P
authors.lastname: Barois
authors.forename: A M
authors.initials: AM
authors.lastname: Levelut
authors.forename: G
authors.initials: G
authors.lastname: Srajer
authors.forename: J
authors.initials: J
authors.lastname: Pollmann
authors.forename: J W
authors.initials: JW
authors.lastname: Goodby
authors.forename: M
authors.initials: M
authors.lastname: Hird