Magnetoresistance of FeCo nanocontacts with current-perpendicular-to-plane spin-valve structure

Hiromi Niu Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki, Shohei Kawasaki, Kousaku Miyake, Masashi Sahashi

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

We have achieved a magnetoresistance (MR) ratio of 7%-10% at a resistance area product (RA) of 0.5-1.5 Ωμm2 by ferromagnetic FeCo nanocontacts in Al nano-oxide-layer (NOL) with current-perpendicular-to-plane spin-valve (CPP-SV) structure. Conductive atomic-force-microscopy shows clear current-path regions of a few nanometers in size surrounded by the Al-NOL. The MR dependence on resistance area product (RA) is well explained by the current-confined-path model assuming that the spin-dependent scattering has an FeCo nanocontact origin, different from tunnel magnetoresistance (TMR). Resistance increases with increasing bias voltage, indicating joule heating by high-current density in nanocontacts, in contrast to TMR. The MR origin is mainly interpreted as spin-dependent scattering due to domain wall formed at ferromagnetic nanocontact.

Original languageEnglish
Pages (from-to)2848-2850
Number of pages3
JournalIEEE Transactions on Magnetics
Volume43
Issue number6
DOIs
Publication statusPublished - 2007 Jun 1

Keywords

  • Conductive atomic-force-microscopy
  • Domain wall
  • Nanocontact magnetoresistance (MR)
  • Spin-valve

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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    Fuke, H. N., Hashimoto, S., Takagishi, M., Iwasaki, H., Kawasaki, S., Miyake, K., & Sahashi, M. (2007). Magnetoresistance of FeCo nanocontacts with current-perpendicular-to-plane spin-valve structure. IEEE Transactions on Magnetics, 43(6), 2848-2850. https://doi.org/10.1109/TMAG.2007.893117