title: Growth mechanism and controlled synthesis of AB-stacked bilayer graphene on Cu-Ni alloy foils.
abstract: Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial "90-10" Cu-Ni alloy foil. However, the mechanism of growth of bilayer graphene on Cu-Ni alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of (12)CH(4) and (13)CH(4)) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechanism of graphene growth on Cu-Ni alloy is by precipitation at the surface from carbon dissolved in the bulk of the alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for (12)C vs(13)C, and slower cooling rate all produced higher graphene coverage on this type of Cu-Ni alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO(2) substrates was controllably synthesized.
authors.affiliation: Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712, United States.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wu
authors.forename: Harry
authors.initials: H
authors.lastname: Chou
authors.forename: Hengxing
authors.initials: H
authors.lastname: Ji
authors.forename: Qingzhi
authors.initials: Q
authors.lastname: Wu
authors.forename: Shanshan
authors.initials: S
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Hao
authors.forename: Junyong
authors.initials: J
authors.lastname: Kang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Ren
authors.forename: Richard D
authors.initials: RD
authors.lastname: Piner
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Ruoff
mesh_terms: D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; C062136:nickel copper alloy; D006108:Graphite; D003300:Copper; D009532:Nickel