Magnetostatic bias in multilayer microwires: theory and experiments
  The hysteresis curves of multilayer microwires consisting of a soft magnetic nucleus, intermediate non-magnetic layers, and an external hard magnetic layer are investigated. The magnetostatic interaction between magnetic layers is proved to give rise to an antiferromagnetic-like coupling resulting in a magnetostatic bias in the hysteresis curves of the soft nucleus. This magnetostatic biasing effect is investigated in terms of the microwire geometry. The experimental results are interpreted considering an analytical model taking into account the magnetostatic interaction between the magnetic layers. 
J. Escrig, S. Allende, D. Altbir, M. Bahiana, J. Torrejon, G. Badini,   M. Vazquez
cond-mat.mes-hall cond-mat.mtrl-sci