title: Deduction of the temperature-dependent structure of the four-layer intermediate smectic phase using resonant X-ray scattering.
abstract: A binary mixture of an antiferroelectric liquid-crystal material containing a selenium atom and a highly chiral dopant is investigated using resonant X-ray scattering. This mixture exhibits a remarkably wide four-layer intermediate smectic phase, the structure of which is investigated over a temperature range of 16K. Analysis of the resonant X-ray scattering data allows accurate measurement of both the helicoidal pitch and the distortion angle as a function of temperature. The former decreases rapidly as the SmC* phase is approached, whilst the latter remains constant over the temperature range studied at 8 degrees +/-3 degrees. We also observe that the senses of the helicoidal pitch and the unit cell of the repeating four-layer structure are opposite in this mixture and that there is no pitch inversion over the temperature range studied.
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester, UK.
authors.forename: P D
authors.initials: PD
authors.lastname: Brimicombe
authors.forename: N W
authors.initials: NW
authors.lastname: Roberts
authors.forename: S
authors.initials: S
authors.lastname: Jaradat
authors.forename: C
authors.initials: C
authors.lastname: Southern
authors.forename: S-T
authors.initials: ST
authors.lastname: Wang
authors.forename: C-C
authors.initials: CC
authors.lastname: Huang
authors.forename: E
authors.initials: E
authors.lastname: Dimasi
authors.forename: R
authors.initials: R
authors.lastname: Pindak
authors.forename: H F
authors.initials: HF
authors.lastname: Gleeson
mesh_terms: D045424:Complex Mixtures / Q000737:chemistry*; D003198:Computer Simulation; D050866:Liquid Crystals / Q000737:chemistry*; D008956:Models, Chemical; D044367:Phase Transition; D012643:Selenium / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D045424:Complex Mixtures; D012643:Selenium