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DY: Dynamik und Statistische Physik

DY 35: Ferro Fluids / Liquid Chrystals

DY 35.1: Vortrag

Mittwoch, 29. März 2006, 14:30–14:45, SCH 251

Growth behaviour of solitary spikes on the surface of magnetic fluids — •Holger Knieling, Reinhard Richter, and Ingo Reh-berg — University of Bayreuth, Institute for experimental physics V, 95440 Bayreuth, Germany

The Rosensweig or normal-field instability on the surface of a ferrofluid is well known. A hexagonal pattern of liquid spikes emerges in a normal magnetic field when a certain threshold of the magnetic induction is surpassed. Recently a stable solitary spike was found in the hysteretic regime of this instability [1]. It can easily be generated by a local perturbation of the surface or the magnetic induction. We now have performed time resolved measurements of its amplitude by recording it with a high-speed camera. The analysis of the pictures results in information about the shape of the structure and the growth behaviour of the amplitude and the volume. The final static shape is compared with numerical calculations.

[1] R. Richter and I.V. Barashenkov, Phys. Rev. Lett. 94, 184503 (2005)