Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 19: Mikro- und nanostrukturierte Materialien I

MA 19.4: Vortrag

Mittwoch, 26. März 2003, 16:00–16:15, HSZ/405

Dependence in domain structures of permalloy particles from its aspect ratio — •Alexander Krasyuk¹, Sergej Nepijko¹, Andreas Oelsner¹, Andrew Kuksov², Claus M. Schneider², and Gerd Schönhense¹ — ¹Institut für Physik, Johannes Gutenberg- Universität, 55099 Mainz, Germany — ²Leibniz-Institut für Festkörper- und Werkstoffforschung, 01069 Dresden, Germany

The magnetic structure of permalloy particles was investigated by means of photoemission electron microscopy (PEEM). Photoelectrons were excitated using left and right circularly polarized synchrotron radiation. The samples have been produced using a photolithography process to obtain particles of rectangular shape and a thickness of about 30 nm. The long axis of all particles was settled fix at 80 µm and their aspect ratio was varied by n:1, being n = 1, 2, 4. The domain structure of these particles was visualized by means of magnetic X-ray circular dichroism (MXCD) imaged with the PEEM. It was shown that domains in particles with an aspect ratio of 1:1 appear mainly in the shape of the well-known Landau-Lifshits patterns. At the higher aspect ratios n:1, Landau-Lifshits structures are repeated n-times in one line forming the domain patterns. Thus, one observes an increase in the number of domains at a reduced particle size. On the other hand, shorting domains with the magnetisation direction parallel to the smaller side of the particle should not be formed, if the rectangular particle appears very narrow. It was observed, that the domain patterns becomes deformed when the distance between the magnetic particles decreases, because of magnetic coupling.