title: Direction-dependent freezing of diamagnetic colloidal tracers suspended in paramagnetic ionic liquids.
abstract: The dynamic behavior of an inverse ferrofluid consisting of diamagnetic, spherical silica particles suspended in the paramagnetic ionic liquid (EMIm)2[Co(NCS)4] is investigated by means of x-ray photon correlation spectroscopy in the presence of an external magnetic field. Dipole-dipole interactions between the diamagnetic holes in the paramagnetic continuum of the suspending medium induce a direction-dependence of the diffusive motion of the colloidal particles: due to a magnetic repulsion perpendicular to the direction of an external field the diffusive motion of the colloidal particles is selectively frozen in this direction.
authors.affiliation: Institut für Chemie, Universität Rostock , Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Passow
authors.forename: Birgit
authors.initials: B
authors.lastname: Fischer
authors.forename: Michael
authors.initials: M
authors.lastname: Sprung
authors.forename: Martin
authors.initials: M
authors.lastname: Köckerling
authors.forename: Joachim
authors.initials: J
authors.lastname: Wagner