Anisotropic magnetoresistance effects in Fe, Co, Ni, Fe 4N, and half-metallic ferromagnet: A systematic analysis

Satoshi Kokado, Masakiyo Tsunoda, Kikuo Harigaya, Akimasa Sakuma

Research output: Contribution to journalArticlepeer-review

105 Citations (Scopus)

Abstract

We theoretically analyze the anisotropic magnetoresistance (AMR) effects of bcc Fe (+), fcc Co (+), fcc Ni (+), Fe 4N (-), and a half-metallic ferromagnet (-). The sign in each parenthesis represents the sign of the AMR ratio observed experimentally. We here use the two-current model for a system consisting of a spin-polarized conduction state and localized d states with spin-orbit interaction. From the model, we first derive a general expression of the AMR ratio. The expression consists of a resistivity of the conduction state of the σ spin (σ = ↑ or ↓), ρ , and resistivities due to s-d scattering processes from the conduction state to the localized d states. On the basis of this expression, we next find a relation between the sign of the AMR ratio and the s-d scattering process. In addition, we obtain expressions of the AMR ratios appropriate to the respective materials. Using the expressions, we evaluate their AMR ratios, where the expressions take into account the values of ρ s↑/ρ s↓ of the respective materials. The evaluated AMR ratios correspond well to the experimental results.

Original languageEnglish
Article number024705
Journaljournal of the physical society of japan
Volume81
Issue number2
DOIs
Publication statusPublished - 2012 Feb

Keywords

  • Anisotropic magnetoresistance effect
  • Half-metallic ferromagnet
  • S-d scattering
  • Spin-orbit interaction
  • Spin-polarized conduction electron
  • Strong ferromagnet
  • Two-current model
  • Weak ferromagnet

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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