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Title: Tunneling magnetoresistance phenomenon utilizing graphene magnet electrode

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 flat-energy-band ferromagnetism. Here, we demonstrate observation of tunneling magnetoresistance (TMR) behaviors on the junction of cobalt/SiO{sub 2}/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 SiO{sub 2}/FGNPA junction also drastically enhances TMR ratios up to ∼100%.
Authors:
; ;  [1] ;  [2] ;  [2] ;  [3] ;  [2] ;  [4]
  1. Faculty of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa 252-5258 (Japan)
  2. Institut Català de Nanociència i Nanotecnologia (ICN2), Campus de la UAB, Edifici ICN2, 08193 Bellaterra, Barcelona (Spain)
  3. (Denmark)
  4. (Spain)
Publication Date:
OSTI Identifier:
22391913
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COBALT; FERROMAGNETISM; GRAPHENE; HYDROGEN; MAGNETORESISTANCE; NANOSTRUCTURES; SILICA; SILICON OXIDES; SPIN; TUNNEL EFFECT