Eur. Phys. J. B 45, 213-218 (2005)
https://doi.org/10.1140/epjb/e2005-00124-5

Structural analysis of ion irradiated polycrystalline NiFe/FeMn exchange bias systems

¹ Fachbereich Physik and Forschungsschwerpunkt MINAS, Erwin-Schrödinger-Strasse 56, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
² Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
³ Institut für Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf, Postfach 510119, 01314 Dresden, Germany

Corresponding author: ^a blomeier@physik.uni-kl.de

Received: 3 September 2004
Revised: 6 December 2004
Published online: 19 April 2005

Abstract

Structural investigations of the ion irradiated polycrystalline NiFe/FeMn exchange bias bilayer system were carried out by means of transmission electron microscopy. Key structural parameters like average grain size, lattice constant, and texture, as well as their dependence upon ion irradiation were determined. This information was extracted from a detailed analysis of a series of bright field images, dark field images, and diffraction patterns. Furthermore a previously established model was tested which ascribes changes in the magnetic properties upon irradiation with 5 keV He⁺ ions to the creation of point defects within the antiferromagnetic layer and to the intermixing between the ferromagnetic and antiferromagnetic layers. The obtained results indirectly support this model by excluding a change of the aforementioned structural parameters as a possible source of the observed modifications of the magnetic properties.