title: Towards intrinsic magnetism of graphene sheets with irregular zigzag edges.
abstract: The magnetism of graphene has remained divergent and controversial due to absence of reliable experimental results. Here we show the intrinsic magnetism of graphene edge states revealed based on unidirectional aligned graphene sheets derived from completely carbonized SiC crystals. It is found that ferromagnetism, antiferromagnetism and diamagnetism along with a probable superconductivity exist in the graphene with irregular zigzag edges. A phase diagram is constructed to show the evolution of the magnetism. The ferromagnetic ordering curie-temperature of the fundamental magnetic order unit (FMOU) is 820 ± 80 K. The antiferromagnetic ordering Neel temperature of the FMOUs belonging to different sublattices is about 54 ± 2 K. The diamagnetism is similar to that of graphite and can be well described by the Kotosonov's equation. Our experimental results provide new evidences to clarify the controversial experimental phenomena observed in graphene and contribute to a deeper insight into the nature of magnetism in graphene based system.
authors.affiliation: Research & Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Lianlian
authors.initials: L
authors.lastname: Chen
authors.forename: Liwei
authors.initials: L
authors.lastname: Guo
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Li
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Jingjing
authors.initials: J
authors.lastname: Lin
authors.forename: Jiao
authors.initials: J
authors.lastname: Huang
authors.forename: Shifeng
authors.initials: S
authors.lastname: Jin
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D006108:Graphite / Q000737:chemistry*; D060526:Magnetic Fields; D059346:Magnets; D008422:Materials Testing; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D006108:Graphite