Cobalt-oxide underlayers for cobalt-ferrite pinned spin valves

We report on the advantages of employing insulating Co-oxide underlayers for spin valves utilizing Co-ferrite as a pinning layer. These underlayers provide for improved crystalline growth of Co-ferrite pinning layers, which can be reduced to as little as 3 nm in thickness while maintaining high coercivity and thermal stability. This allows a typical antiferromagnetically pinned spin valve to fit into a 50 nm gap, which is anticipated for recording densities >100 Gbit/in2. Magnetoresistance values ∼7%, excellent stability, and free layer properties are observed and pinned which is comparable to present PtMn based sensors of similar thickness. © 2002 American Institute of Physics.