Eur. Phys. J. B 45, 181-184 (2005)
https://doi.org/10.1140/epjb/e2005-00183-6

Exchange bias on epitaxial Ni films due to ultrathin NiO layer

¹ University of Toledo, Toledo, OH 43606, USA
² IMRE, National University of Singapore, Singapore 117602

Corresponding author: ^a alukasz@physics.utoledo.edu

Received: 15 September 2004
Revised: 29 April 2005
Published online: 28 June 2005

Abstract

Exchange anisotropy refers to the effect that an antiferromagnetic (AF) layer grown in contact with a ferromagnetic (FM) layer has on the magnetic response of the FM layer. The most notable changes in the FM hysteresis loop due to the surface exchange coupling are a coercivity enhanced over the value typically observed in films grown on a nonmagnetic substrate, and a shift in the hysteresis loop of the ferromagnet away from the zero field axis. A typical observation is that the thickness of the antiferromagnet needs to exceed a critical value before exchange bias is observed. Here we report on the exchange bias properties observed in an epitaxial Ni/NiO system where a thin NiO layer forms spontaneously and is observed after annealing epitaxial Ni films MBE grown on MgO substrates.