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NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2014, 5 (1), P. 25–38

GRAPHENE EDGE SPINS: SPINTRONICS AND MAGNETISM IN GRAPHENE NANOMESHES

T. Hashimoto – Faculty of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan
S. Kamikawa – Faculty of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan
Y. Yagi – Faculty of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan
J. Haruyama – Faculty of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan; J-haru@ee.aoyama.ac.jp
H. Yang – SPINTEC, CEA/CNRS/UJF-Grenoble 1/Grenoble-INP, 38054, Grenoble cedex 9, France
M. Chshiev – SPINTEC, CEA/CNRS/UJF-Grenoble 1/Grenoble-INP, 38054, Grenoble cedex 9, France

We have fabricated low-defect graphene nanomeshes (GNMs) by using a non-lithographic method and observed large-amplitude ferromagnetism even at room temperature, only when pore edges of the GNMs were hydrogen-terminated. The observed correlation between the inter-pore spacing and magnetism and also magnetic force microscope observations suggest that it is attributed to polarzied electron spins localized at the zigzag-type atomic structured pore-edges. The magnetic moment per edge dangling bond (~0.3 μB) is also in quantitative agreement with two theories. Moreover, a spin pumping effect is found for fields applied in parallel with the GNM planes in few-layer ferromagnetic GNMs, while a magnetoresistance (MR) hysteresis loop is observed under perpendicular fields. The present ferromagnetic GNMs must also realize rare-element free, invisible, flexible, and ultra-light (wearable) magnets and spintronic devices, which can overcome environmental and material-resource problems.

Keywords: Graphene, Edges, Polarized spins, Magnetism, Spintronics, Flat band.

PACS 75.70.i, 75.30.m, 75.50.Dd, 75.75.c

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