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arXiv · 1406.1119

Hyperfine magnetic field in ferromagnetic graphite

Jair C. C. Freitas·Wanderlã L. Scopel·Wendel S. Paz·Leandro V. Bernardes·Francisco E. Cunha-Filho·Carlos Speglich·Fernando M. Araújo-Moreira·Damjan Pelc·Tonči Cvitanić·Miroslav Požek
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Abstract

Information on atomic-scale features is required for a better understanding of the mechanisms leading to magnetism in non-metallic, carbon-based materials. This work reports a direct evaluation of the hyperfine magnetic field produced at 13C nuclei in ferromagnetic graphite by nuclear magnetic resonance (NMR). The experimental investigation was made possible by the results of first-principles calculations carried out in model systems, including graphene sheets with atomic vacancies and graphite nanoribbons with edge sites partially passivated by oxygen. A similar range of maximum hyperfine magnetic field values (18-21T) was found for all systems, setting the frequency span to be investigated in the NMR experiments; accordingly, a significant 13C NMR signal was detected close to this range without any external applied magnetic field in ferromagnetic graphite.

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Jair C. C. Freitas, Wanderlã L. Scopel, Wendel S. Paz, Leandro V. Bernardes, Francisco E. Cunha-Filho, Carlos Speglich, Fernando M. Araújo-Moreira, Damjan Pelc, Tonči Cvitanić, Miroslav Požek. 2014-06-04. Hyperfine magnetic field in ferromagnetic graphite. https://doi.org/10.1038/srep14761

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