title: Sedimentation profiles of systems with reentrant melting behavior.
abstract: We examine sedimentation density profiles of star polymer solutions as an example of colloidal systems in sedimentation equilibrium that exhibit reentrant melting in their bulk phase diagram. Phase transitions between a fluid and a fluid with an intercalated solid are observed below a critical gravitational strength alpha*. Characteristics of the two fluid-solid interfaces in the density profiles occurring in Monte Carlo simulations for alpha<alpha* are in agreement with scaling laws put forth in the framework of a phenomenological theory. Furthermore, we detect density oscillations at the fluid-gas interface at high altitudes for high-gravitational fields, which are verified with density-functional theory and should be observable in surface scattering experiments.
authors.affiliation: Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany. joachim@thphy.uni-duesseldorf.de
authors.forename: J
authors.initials: J
authors.lastname: Dzubiella
authors.forename: H M
authors.initials: HM
authors.lastname: Harreis
authors.forename: C N
authors.initials: CN
authors.lastname: Likos
authors.forename: H
authors.initials: H
authors.lastname: Löwen