Determination of the hyperfine magnetic field in magnetic carbon-based materials: DFT calculations and NMR experiments

作者：Freitas Jair C C; Scopel Wanderla L; Paz Wendel S; Bernardes Leandro V; Cunha Filho Francisco E; Speglich Carlos; Araujo Moreira Fernando M; Pelc Damjan; Cvitanic Tonci; Pozek Miroslav^*

来源：Scientific Reports, 2015, 5(1): 14761.

DOI：10.1038/srep14761

The prospect of carbon-based magnetic materials is of immense fundamental and practical importance, and information on atomic-scale features is required for a better understanding of the mechanisms leading to carbon magnetism. Here we report the first direct detection of the microscopic magnetic field produced at C-13 nuclei in a ferromagnetic carbon material by zero-field nuclear magnetic resonance (NMR). Electronic structure calculations carried out in nanosized model systems with different classes of structural defects show a similar range of magnetic field values (18-21 T) for all investigated systems, in agreement with the NMR experiments. Our results are strong evidence of the intrinsic nature of defect-induced magnetism in magnetic carbons and establish the magnitude of the hyperfine magnetic field created in the neighbourhood of the defects that lead to magnetic order in these materials.

• 出版日期2015-10-5