title: Chiral random grain boundary phase of achiral hockey-stick liquid crystals.
abstract: A disordered chiral conglomerate, the random grain boundary (RGB) phase, has been observed below the smectic A liquid crystal phase of an achiral, hockey-stick molecule. In cells, the RGB phase appears dark between crossed polarizers but decrossing the polarizers reveals large left- and right-handed chiral domains with opposite optical rotation. Freeze-fracture transmission electron microscopy reveals that the RGB phase is an assembly of randomly oriented blocks of smectic layers, an arrangement that distinguishes the RGB from the dark, chiral conglomerate phases of bent-core mesogens. X-ray diffraction indicates that there is significant layer shrinkage at the SmA-RGB phase transition, which is marked by the collapse of layers with long-range order into small, randomly oriented smectic blocks.
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, CO 80309-0390, USA. noel.clark@colorado.edu.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Glaser
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Maclennan
authors.forename: Noel A
authors.initials: NA
authors.lastname: Clark