Exchange-biased ferromagnetic tunnel junctions via reactive evaporation of nickel oxide films

Nickel oxide films, prepared by reactive evaporation at room temperature, have shown good properties to be used as an exchange biasing antiferromagnet on ferromagnetic tunnel junctions. For instance, in the case of Co/Al2O3/Co/NiO junction, NiO shows an exchange field of 17 Oe at 295 K, increasing to 174 Oe at 77 K, and the junction magnetoresistances are 17% at 295 K and 22% at 77 K. The temperature dependence of the exchange field and junction magnetoresistance are also investigated between 77 K and 400 K.