Polycrystalline CPP-GMR devices using textured Co 2 Fe(Ga 0.5 Ge 0.5 ) Heusler alloy layer and conductive Mg 0.5 Ti 0.5 O x buffer layer

摘要: Current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices with Co-based Heusler alloys have recently drawn considerable attention due to their potential application as read sensors for ultrahigh density magnetic recording.1,2,3,4 With a non-magnetic Ag spacer layer, the resistance change-area product (ΔRA) of epitaxial pseudo spin valves (PSVs) on single crystalline (001) MgO substrates has exceeded 10 mΩ μm2 by using quaternary ferromagnetic (FM) such Co 2 Fe(Ga 0.5 Ge ) (CFGG) and Fe 0.4 Mn 0.6 Si (CFMS). From practical point view, however, we need develop CPP-GMR polycrystalline thin films at relatively low annealing temperatures ( textured buffer layer showed favorable device thermal stability moderate ΔRA 5.8 400°C was obtained. Nevertheless, it is not industrially viable because an insulator cannot be used fabrication actual sensors. In this work, report properties microstructure PSV FM CFGG conductive Mg Ti O x (MTO)6 deposited chemically-mechanically polished (CMP) Ta/Cu/Ta electrode thermally oxidized substrates. Relatively large 6.6 desirable interfacial smoothness make promising candidate head design.