title: Microscopic origins of first-order Sm-A-Sm-C phase behavior in de Vries smectic liquid crystals.
abstract: We explore the phase behavior of tilted hard rods as a model of de Vries smectic behavior and the first order smectic-C (Sm-C) to smectic-A (Sm-A) phase transition. The free energy cost of azimuthal rotation of a molecule away from the local tilt direction is calculated via umbrella sampling. This calculation is used to map the hard rod system onto a lattice spin system which shows a cross-over from a continuous to first-order phase transition as the tilt of the rods is increased. This analysis offers a natural explanation of the first-order Sm-A-Sm-C phase transition common to de Vries smectics.
authors.affiliation: Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Zachary V
authors.initials: ZV
authors.lastname: Kost-Smith
authors.forename: Paul D
authors.initials: PD
authors.lastname: Beale
authors.forename: Noel A
authors.initials: NA
authors.lastname: Clark
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Glaser
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D050866:Liquid Crystals / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D012399:Rotation