  Magnetic systems exhibiting exchange bias effect are being considered as
materials for applications in data storage devices, sensors and biomedicine. As
the size of new mag- netic devices is being continuously reduced, the influence
of thermally induced instabilities in magnetic order has to be taken into
account during their fabrication process. In this study we show the influence
of superparamagnetism on magnetic properties of exchange-biased [CoO/Co/Pd]10
multilayer. We find that the process of progressive thermal blocking of the
superparamagnetic clusters causes an unusually fast rise of the exchange
anisotropy field and coercivity, and promotes the easy axis switching to
out-of-plane direction.
