title: Observations of the liquid-crystal analog of the abrikosov phase.
abstract: Freeze-fracture transmission electron micrographs of the smectic A(*) phase confirm the twist grain boundary model of Renn and Lubensky. The fracture surface has an undulating structure with a 0.5-micrometer helical pitch parallel to 4.1-nanometer smectic layers. The layers are disrupted by a lattice of screw dislocations oriented normal to the helical axis. Optical diffraction shows that rotation of smectic blocks occurs in discrete steps of about 17 degrees ; hence, the screw dislocations are 14 to 15 nanometers apart and the grain boundaries are 24 nanometers apart. These observations show that the SmA(*) phase is the liquid-crystal analog of the Abrikosov phase in superconductors.
authors.forename: K J
authors.initials: KJ
authors.lastname: Ihn
authors.forename: J A
authors.initials: JA
authors.lastname: Zasadzinski
authors.forename: R
authors.initials: R
authors.lastname: Pindak
authors.forename: A J
authors.initials: AJ
authors.lastname: Slaney
authors.forename: J
authors.initials: J
authors.lastname: Goodby