Enhancement of magnetoresistance by ultra-thin Zn wüstite layer

We have investigated a hybrid magnetic material composed of ultra-thin oxide spin-filtering layer/ferromagnetic layer (FML) for magnetoresistance (MR) enhancement. Using Zn-Fe oxide/Fe50Co50 as a free layer in current-perpendicular-to-plane giant magnetoresistive films, the MR ratio and ΔRA (the change of resistance area product) were enhanced to 26.0% and 52 mΩ μm2 at a small RA (resistance area product) of about 0.2 Ω μm2, respectively. Structural analysis revealed that the Zn wustite structure is responsible for the enhancement of the MR ratio, and spin-polarization of wustite/FML is higher than that of spinel ferrite/FML.

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