Eur. Phys. J. B 45, 175-179 (2005)
https://doi.org/10.1140/epjb/e2005-00180-9

Complex angular dependence of exchange bias on (001) epitaxial NiO-Co bilayers

¹ LNMH-CNRS, ONERA, 2 avenue Edouard Belin, 31400 Toulouse, France
² CEMES CNRS, 29 rue Jeanne Marvig 31055 Toulouse, France

Corresponding author: ^a jfbobo@onecert.fr

Received: 15 September 2004
Revised: 19 April 2005
Published online: 28 June 2005

Abstract

We have sputter-deposited NiO-Co bilayers on MgO(001) substrates. NiO and Co grow epitaxially on MgO and reproduce its fcc structure. The high quality of our samples, in terms of flatness and crystallographic coherence of the interface, allows the observation of an additional fourfold magnetic anisotropy term by standard magnetometry. This term is induced by interfacial interaction assigned to the same origin as exchange bias. Additional measurements of exchange bias azimuthal dependence versus the crystallographic axes of the film plane reveal unusual behaviors with several sign changes related to this fourfold anisotropy.