Regensburg 2007 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 9: POSTER: Colloids and Nanoparticles

CPP 9.10: Poster

Monday, March 26, 2007, 16:00–18:00, Poster B

Layer and lane formation in driven magnetic colloidal particles — •Marcin Zientara, Michael Koppl, Artur Erbe, and Paul Leiderer — Universität Konstanz, FB Physik, Germany

The process of lane formation is a nonequlibrium phase transition occuring in two-component systems under the action of external forces. It aims at an increase of transport or motion efficiency if particles are driven by forces acting in opposite directions. The simplest situation to imagine is a mixture of particles, half of which has a positive charge and half has a negative charge. Such particles can be moved in opposite directions, if an external eletric field is applied. If the force exceeds a certain threshold, the motions will separate and ordered lanes will appear. This phenomenon has been studied theoretically in a wide range of systems. We show experimental results of paramagnetic particles confined in a narrow channel driven by gravity. In this system layering of the particles leads to a similar ordering phenomenon. In a mixture of magnetic and non-magnetic particles lane formation is expected, if the particles are driven in opposite directions by application of a gradient in the magnetic field in combination with gravity.