Current-perpendicular-to-the-plane giant magnetoresistance in structures with half-metal materials laminated between CoFe layers

Abstract

A current-perpendicular-to-the-plane spin-valve (CPP-SV) structure having half-metal materials laminated between CoFe layers was investigated. A CPP-SV film having a CoMnGe free layer had a resistance-change-area product ΔRA of 0.9 mΩ μm2, almost the same as that of a CPP-SV film having a simple CoFe free layer. But the ΔRA of a CPP-SV film with a CoFe/CoMnGe/CoFe sandwiched free layer was 1.6 mΩ μm2. CPP-SV films having CoFe/iron-added-magnetite/CoFe sandwiched layers were also investigated and found to have a ΔRA of ≈2 mΩ μm2. We found that a CoFe/half-metal/CoFe sandwiched layer was a stronger source of spin-dependent scattering than a CoFe layer and simple half-metal layer.