Current perpendicular-to-plane giant magnetoresistance devices using half-metallic Co2Fe0.4Mn0.6Si electrodes and a Ag-Mg spacer

T. Kubota, Y. Ina, M. Tsujikawa, S. Morikawa, H. Narisawa, Z. Wen, M. Shirai, K. Takanashi

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Current perpendicular-to-plane (CPP) giant magnetoresistance (GMR) effects in devices including Co2Fe0.4Mn0.6Si (CFMS)/Ag100-xMgx/CFMS structures were investigated theoretically and experimentally. First-principles transport calculation revealed that the Fermi surface matching between CFMS and L12 Ag3Mg is better than that between CFMS and fcc-Ag. In the experiments the Mg composition, x was changed from 0 to 26 at.%, in which both face centered cubic phase and L12 phase of Ag-Mg alloys are included depending on the Mg composition. It was confirmed by a cross-sectional high-angle annular dark field scanning transmission electron microscope (HAADF-STEM) image that the Ag-Mg spacer layer with L12 ordered phase was successfully fabricated for x = 22 at.%. The maximum CPP-GMR ratio and the change of the areal resistance () were 56% and 20 mm2, respectively, for x = 22 at.% at room temperature, which is much higher than that of the conventionally used pure Ag spacer devices. It was suggested from the HAADF-STEM images and the results of the temperature dependence of CPP-GMR effects that the diffusion of Mn atoms occurred less at the CFMS/Ag-Mg interfaces for the L12 ordered Ag-Mg spacer devices than the Ag spacer devices, which might be a key factor for the enhancement of the value. The newly developed L12 Ag-Mg spacer is a promising material for realizing large of the CPP-GMR devices.

Original languageEnglish
Article number014004
JournalJournal of Physics D: Applied Physics
Volume50
Issue number1
DOIs
Publication statusPublished - 2017 Jan 11

Keywords

  • CPP-GMR
  • Heusler alloy
  • half-metal
  • magnetoresistance effect
  • ordered alloy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

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