Ferromagnetism in Semihydrogenated Graphene Sheet

摘要: Single layer of graphite (graphene) was predicted and later experimentally confirmed to undergo metal-semiconductor transition when fully hydrogenated (graphane). Using density functional theory we show that half the hydrogen in this graphane sheet is removed, resulting semihydrogenated graphene (which refer as graphone) becomes a ferromagnetic semiconductor with small indirect gap. Half-hydrogenation breaks delocalized pi bonding network graphene, leaving electrons unhydrogenated carbon atoms localized unpaired. The magnetic moments at these sites couple ferromagnetically an estimated Curie temperature between 278 417 K, giving rise infinite structural integrity homogeneity. This very different from widely studied finite nanostrucures such one-dimensional nanoribbons two-dimensional nanoholes, where zigzag edges are necessary for magnetism. From graphone, system evolves metallic semiconducting nonmagnetic magnetic. Hydrogenation provides novel way tune properties unprecedented potentials applications.