Article abstract
Nature Physics 5, 840 - 844 (2009)
Published online: 4 October 2009 | doi:10.1038/nphys1399
Subject Category: Condensed-matter physics
Room-temperature ferromagnetism in graphite driven by two-dimensional networks of point defects
J. 
ervenka1,3,
M. I. Katsnelson2
&
C. F. J. Flipse1
Abstract
Understanding the mechanism of ferromagnetism in carbon-based materials, which contain only s and p electrons in contrast to traditional ferromagnets based on 3d or 4f electrons, is challenging. Here, we demonstrate direct evidence for ferromagnetic order locally at defect structures in highly oriented pyrolytic graphite (HOPG) with magnetic force microscopy and in bulk magnetization measurements at room temperature. Magnetic impurities have been excluded as the origin of the magnetic signal. The observed ferromagnetism has been attributed to originate from localized electron states at grain boundaries of HOPG, forming two-dimensional arrays of point defects. The theoretical value of the magnetic ordering temperature based on weak interlayer coupling and/or magnetic anisotropy is comparable to the experimental value. The unusual chemical environment of defects bonded in graphitic networks can reveal the role of the s and p electrons, creating new routes for spin transport in carbon-based materials.
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Institute of Molecules and Materials, Radboud University of Nijmegen, NL-6525 ED Nijmegen, The Netherlands
- Present address: Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, CZ-162 53 Prague 6, Czech Republic
Correspondence to: C. F. J. Flipse1 e-mail: C.F.J.Flipse@tue.nl
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Correlated oxides Another brick in the wallNature Physics News and Views (01 May 2006)
Irradiated materials Defects break symmetry rulesNature Materials News and Views (01 May 2003)
See all 7 matches for News And ViewsRESEARCH
Half-metallic graphene nanoribbonsNature Letters to Editor (16 Nov 2006)
Collective behaviour in two-dimensional cobalt nanoparticle assemblies observed by magnetic force microscopyNature Materials Article (01 Apr 2004)
See all 76 matches for Research
