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

Author(s)

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

• Document type: Journal article
• Source: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 33, n. 10, p. 8-pg., 2021-03-10.

Abstract

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)

• FAPESP's process: 07/54829-5 - Electronic and geometric structure of nano-materials: synchrotron radiation studies
• Grantee: Richard Landers
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/21402-8 - Growth and characterization of two-dimensional heterostructures: transition metal dichalcogenides on graphene and hexagonal boron nitride
• Grantee: Luis Henrique de Lima
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 07/08244-5 - Study of the magnetic properties of Pd and PdAu ultrathin films and nanoparticles by using XMCD
• Grantee: Abner de Siervo
• Support Opportunities: Regular Research Grants