Znウスタイトスピンフィルタリング層による磁気抵抗効果の増大

抄録

  We have investigated a new magnetic material composed of ultra-thin oxide spin-filtering layer (SFL)/ferromagnetic layer (FML) for magnetoresistance (MR) enhancement. By inserting Zn-Fe oxide as a SFL material in current-perpendicular-to-plane giant magnetoresistive (CPP-GMR) films, the MR ratio and ΔRA (the change of resistance area product) were enhanced to 26.0% and 52 mΩμm² at a small RA (resistance area product) of about 0.2 mΩμm², respectively. Structural analysis revealed that the Zn wüstite structure is responsible for the enhancement of the MR ratio, and wüstite/FML structure has higher spin-polarization than that for spinel ferrite/FML. Although wüstite has not been predicted to be high spin-polarization material and little experimental data on the transport property has been reported, our results indicate that wüstite has potential as high spin-polarization material for future spin electronics.