THE EUROPEAN PHYSICAL JOURNAL B – CONDENSED MATTER AND COMPLEX SYSTEMS 45, 223 (2005)

M. Ziese, R. Höhne, A. Bollero, H.-C. Semmelhack, P. Esquinazi and K. Zimmer

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.