title: Effect of external electric fields on the phase behavior of colloidal silica rods.
abstract: We examine the effect of external electric fields on the behavior of colloidal silica rods. We find that the electric fields can be used to induce para-nematic and para-smectic phases, and to reduce the number of defects in smectic phases. At high field strengths, a new crystal structure was observed that consisted of strings of rods ordered in a hexagonal pattern in which neighboring rods were shifted along their length. We also present a simple model to describe this system, which we used in computer simulations to calculate the phase diagram for rods of L/D = 6, with L the end-to-end length of the rods and D the diameter of the rods. Our theoretical predictions for the phase behavior agree well with the experimental observations.
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands. A.vanBlaaderen@uu.nl.
authors.forename: Anke
authors.initials: A
authors.lastname: Kuijk
authors.forename: Thomas
authors.initials: T
authors.lastname: Troppenz
authors.forename: Laura
authors.initials: L
authors.lastname: Filion
authors.forename: Arnout
authors.initials: A
authors.lastname: Imhof
authors.forename: René
authors.initials: R
authors.lastname: van Roij
authors.forename: Marjolein
authors.initials: M
authors.lastname: Dijkstra
authors.forename: Alfons
authors.initials: A
authors.lastname: van Blaaderen