Structural characterization of Co_100-xFe_x nano-oxide layer

For the structural characterization of a Co100-x Fex nano-oxide layer (NOL), the exchange bias properties of the Co100-x Fex -natural oxidized NOL in the specular spin-valve (SPSV) system were investigated. The exchange bias energy (Jex) increased monotonically with the increasing Fe content for the Co100-x Fex -NOL. The enhancement of both the magnetoresistance ratio and the exchange bias field (Hex) was realized by increasing the Fe content in the Co100-x Fex -NOL. It should be mentioned that Hex more than 800 Oe is obtained by the insertion of Co30 Fe70 -NOL, even in NOL-SPSV, which is a remarkably higher pinning field than that ever reported on IrMn-SV. This high exchange bias field is considered to be realized by the formation of an Fe-rich fcc phase at the interface of IrMn.