Magnetic properties of nanographite with modified zigzag edges Original Research Article

Newly proposed aromatic molecules and graphene fragments are shown to have the high-spin ground state by the first-principles electronic structure calculations. Our strategy to predict magnetic carbon materials is based on our previous conclusion that mono-hydrogenated, di-hydrogenated or mono-fluorinated zigzag edges of honeycomb networks are magnetic. Structural optimization as well as determination of the electronic states was performed for various nanographite ribbons and high-spin molecules, e.g. 1,8,9-di-hydro-anthracene, C19H14 and C14F13. For hydrogenated molecules and ribbons, the total spin S determined by the LSDA calculation coincides with the value expected from a counting rule for the total spin on a bipartite network. However, S depends on structures of fluorinated nanographite.