We use ab initio methods to study the atomic, electronic, and magnetic structure of nitrogen impurities in graphite and carbon nanotubes. We show that the probable configurations for the N impurity atoms are bridgelike adatoms on graphene sheets/nanotubes, substitutional sites and intercalated N2 molecules. We further calculate the migration energy barrier for an N adatom on the graphite surface and the activation energy for the coalescence of two N adatoms into a molecule, which are 1.1eV and 0.8eV, respectively. We also find that the N adatom has a magnetic moment of 0.6μB and that substitutional N enhances the magnetism of C adatoms on graphite and nanotubes, acting as a general promoter of magnetism in carbon systems.
|Number of pages||6|
|Journal||Physical Review B|
|Publication status||Published - 2005|
|MoE publication type||A1 Journal article-refereed|