Tunneling magnetoresistance phenomenon utilizing graphene magnet electrode

T. Hashimoto, S. Kamikawa, D. Soriano, Jesper Goor Pedersen, S. Roche, J. Haruyama

Research output: Contribution to journalJournal articleResearchpeer-review

2184 Downloads (Pure)

Abstract

Using magnetic rare-metals for spintronic devices is facing serious problems for the environmental contamination and the limited material-resource. In contrast, by fabricating ferromagnetic graphene nanopore arrays (FGNPAs) consisting of honeycomb-like array of hexagonal nanopores with hydrogen-terminated zigzag-type atomic structure edges, we reported observation of polarized electron spins spontaneously driven from the pore edge states, resulting in rare-metal-free flatenergy- band ferromagnetism. Here, we demonstrate observation of tunneling magnetoresistance (TMR) behaviors on the junction of cobalt/SiO2/FGNPA electrode, serving as a prototype structure for future rare-metal free TMR devices using magnetic graphene electrodes. Gradual change in TMR ratios is observed across zero-magnetic field, arising from specified alignment between pore-edge- and cobalt-spins. The TMR ratios can be controlled by applying back-gate voltage and by modulating interpore distance. Annealing the SiO2/FGNPA junction also drastically enhances TMR ratios up to similar to 100%. (C) 2014 AIP Publishing LLC.
Original languageEnglish
Article number183111
JournalApplied Physics Letters
Volume105
Issue number18
ISSN0003-6951
DOIs
Publication statusPublished - 2014

Keywords

  • PHYSICS,
  • III-V SEMICONDUCTORS
  • EDGES
  • NANORIBBONS
  • JUNCTIONS
  • ZIGZAG

Cite this

Hashimoto, T., Kamikawa, S., Soriano, D., Pedersen, J. G., Roche, S., & Haruyama, J. (2014). Tunneling magnetoresistance phenomenon utilizing graphene magnet electrode. Applied Physics Letters, 105(18), [183111]. https://doi.org/10.1063/1.4901279