Berlin 2008 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 6: Ferrofluids

DY 6.1: Talk

Monday, February 25, 2008, 14:30–14:45, A 053

The Rosensweig instability in thermoreversible ferrogels — •Christian Gollwitzer¹, Marina Krekhova², Ingo Rehberg¹, Günter Lattermann², and Reinhard Richter¹ — ¹Experimentalphysik V, Universität Bayreuth — ²Makromolekulare Chemie I, Universität Bayreuth

Ferrogels are an interesting new class of materials that enhance the properties of magnetic fluids by elastic components [1]. According to Bohlius et al. [2], the famous Rosensweig instability should also be possible in ferrogels. Compared to the pure ferrofluid, the critical magnetic field is shifted to higher values due to elastic forces, and the critical wavenumber remains the same.

We use a thermoreversible ferrogel [3] and expose it to a homogeneous magnetic field. By controlling the temperature we can easily change the elastic modulus over several orders of magnitude. The surface profile of the ferrogel is then recorded using an X-ray technique.

[1] Zrinyi, M., Barsi, L., Szabo, D. & Kilian, H.-G. 1997 The Journal of Chemical Physics 106 (13), 5685–5692.
[2]Bohlius, Brand & Pleiner 2006 Z. Phys. Chem 220, 97
[3]Lattermann, G. & Krekhova, M. 2006 Macromol. Rapid Commun. 27, 1373–1379.