• 文献标题:   Selecting 'convenient observers' to probe the atomic structure of CVD graphene on Ir(111) via photoelectron diffraction
  • 文献类型:   Article
  • 作  者:   BARRETO L, DE LIMA LH, MARTINS DC, SILVA C, FERREIRA RCD, LANDERS R, DE SIERVO A
  • 作者关键词:   graphene, photoelectron diffraction, moir #233
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:  
  • 被引频次:   4
  • DOI:   10.1088/1361-648X/abceff
  • 出版年:   2021

▎ 摘  要

CVD graphene grown on metallic substrates presents, in several cases, a long-range periodic structure due to a lattice mismatch between the graphene and the substrate. For instance, graphene grown on Ir(111), displays a corrugated supercell with distinct adsorption sites due to a variation of its local electronic structure. This type of surface reconstruction represents a challenging problem for a detailed atomic surface structure determination for experimental and theoretical techniques. In this work, we revisited the surface structure determination of graphene on Ir(111) by using the unique advantage of surface and chemical selectivity of synchrotron-based photoelectron diffraction. We take advantage of the Ir 4f photoemission surface state and use its diffraction signal as a probe to investigate the atomic arrangement of the graphene topping layer. We determine the average height and the overall corrugation of the graphene layer, which are respectively equal to 3.40 +/- 0.11 angstrom and 0.45 +/- 0.03 angstrom. Furthermore, we explore the graphene topography in the vicinity of its high-symmetry adsorption sites and show that the experimental data can be described by three reduced systems simplifying the moire supercell multiple scattering analysis.