Eur. Phys. J. B 45, 223-230 (2005)
https://doi.org/10.1140/epjb/e2005-00177-4

Size and shape dependence of the exchange-bias field in exchange-coupled ferrimagnetic bilayers

¹ Division of Superconductivity and Magnetism, University of Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany
² Institute for Surface Modification, 04318 Leipzig, Germany

Corresponding author: ^a ziese@physik.uni-leipzig.de

Received: 15 September 2004
Revised: 20 April 2005
Published online: 28 June 2005

Abstract

Exchange biasing was studied in an exchange-spring system consisting of two ferrimagnetic films with different coercivity. Magnetite and Co-Fe ferrite were chosen as the soft and hard magnetic bilayer components, respectively. The samples were epitaxially grown on MgO single crystal substrates by pulsed laser deposition. The exchange-bias field was investigated as a function of system size and shape, magnetic field direction and magnetization reversal in the hard layer. A clear dependence of the exchange-bias field on the sample size and shape was found. This was attributed to an interplay between exchange and dipolar energies. Micromagnetic simulations agree with the experimental results.