Regensburg 2013 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 29: Micro- and Nanostructured Magnetic Materials

MA 29.8: Vortrag

Mittwoch, 13. März 2013, 17:00–17:15, H23

Studying the magnetization reversal of a permalloy antidot array by magnetic force microscopy — •Steffen Nothelfer, Felix Haering, Ulf Wiedwald, Berndt Koslowski, and Paul Ziemann — Ulm University, Institute of Solid State Physics, D-89069 Ulm, Germany

We study the magnetization of hexagonally arranged antidot arrays in permalloy thin films by analyzing the stray field of such films by means of magnetic force microscopy (MFM) in a variable magnetic field. Our investigations focus on such systems for which the magnetization behavior is governed by a spin ice rule, typically observed for lattice constants below 500nm and antidot diameters above 330nm. In this case, a simple magnetization model provides the possibility of reconstructing the magnetization pattern of the film from MFM images depending on the external magnetic field. A good correspondence of measurements employing MFM and X-ray magnetic circular dichroism [1,2] is found. Additionally, the controlled magnetization reversal of the film enables an isolation of the magnetic interaction from other interactions, e.g., the van der Waals interaction. We find a surprising exponential decay of the field perpendicular to the surface in the range of 0.03-0.3 lattice constants of the antidot lattice. This result agrees well with micromagnetic simulations.

[1] E. Mengotti, L. Heyderman, A. Fraile Rodríguez, F. Nolting, R. V. Hügli, and Hans-Benjamin Braun, Nature Physics 7, (2011).

[2] F. Hearing, U. Wiedwald, T. Häberle, L. Han, A. Plettl, B. Koslowski, P. Ziemann, submitted to Nanotechnology.