Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 20: Mikromagnetismus / Computational Magnetics

MA 20.1: Vortrag

Mittwoch, 26. März 2003, 17:30–17:45, HSZ/405

Direct Observation of Internal Spin-Structure of Magnetic Vortex Cores — •M Bode, A Wachowiak, J Wiebe, O Pietzsch, M Morgenstern, and R Wiesendanger — Institute of Applied Physics and Microstructure Research Center, University of Hamburg, Jungiusstr. 11, D-20355 Hamburg, Germany

Thin film nanoscale elements with a curling magnetic structure (vortex) are a promising candidate for future non-volatile data storage devices. Their properties are strongly influenced by the spin-structure in the vortex core. We have used spin-polarized scanning tunneling microscopy on nanoscale iron islands, to probe for the first time the internal spin-structure of magnetic vortex cores. Using tips coated with a layer of antiferromagnetic chromium, we obtained images of the curling in-plane magnetization around and of the out-of-plane magnetization inside the core region. The experimental data are compared to micromagnetic simulations. The results confirm theoretical predictions that the size and the shape of the vortex core as well as its magnetic field dependence is governed by only two material parameters, i.e. the exchange stiffness and the saturation magnetization which determines the stray field energy.