Selecting 'convenient observers' to probe the atomic structure of CVD graphene on Ir(111) via photoelectron diffraction

Autor(es)

Barreto, Lucas ; de Lima, Luis Henrique ; Martins, Daniel Coutinho ; Silva, Caio ; de Campos Ferreira, Rodrigo Cezar ; Landers, Richard ; de Siervo, Abner

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 33, n. 10, p. 8-pg., 2021-03-10.

Resumo

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. (AU)

• Processo FAPESP: 07/54829-5 - Estrutura eletrônica e geométrica de nano materiais: um estudo por radiação sincroton
• Beneficiário: Richard Landers
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/21402-8 - Crescimento e caracterização de heteroestruturas bidimensionais: dicalcogenetos de metais de transição sobre grafeno e nitreto de boro hexagonal
• Beneficiário: Luis Henrique de Lima
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 07/08244-5 - Estudo das propriedades magnéticas de filmes ultrafinos e nanopartículas de Pd e PdAu via XMCD
• Beneficiário: Abner de Siervo
• Modalidade de apoio: Auxílio à Pesquisa - Regular