Carbon-based nanostructures on surfaces

Oxidation of graphene and nanotubes
(Baris Malcioglu and Stefano Fabris)

From the first wood fire of prehistoric man to the steel mills of today it has been a continuous burning of wood and coke. But what happens when carbon burns? Understanding combustion at the atomic scale is challenging particularly for the novel C-based nanostructures, like graphene and nanotubes. We study how oxygen attacks and dismantles the C networks of these systems by combining DFT calculations with photoemission spectroscopy and scanning tunneling microscopy, revealing the atomic and bonding rearrangement following reaction with atomic and molecular oxygen.

In collaboration with:

  • ELETTRA - Esca beamline (A. Barinov and M. Kiskinova)
  • CNR-INFM TASC (F. Esch)

Defect-controlled metal transport on carbon nanotubes
(Hande Ustunel, Stefano Fabris, and Stefano Baroni)

The unique electronic, mechanical, and transport properties of C nanotubes (CNTs), their confinement anisotropy, as well as their adaptive functionalization by adsorption of foreign atoms have made them a key material in nanotechnology. This project addresses the diffusion mechanisms of metal atoms (In) along multiwalled CNTs by combining photoemission spectromicroscopy and density functional theory calculations. Our study reveales that metal transport is controlled by the concentration of defects in the C network and proceeds via adatom hopping between C vacancies.

In collaboration with:

  • ELETTRA - Esca beamline (A. Barinov and M. Kiskinova)

A. Barinov, H. Üstünel, S. Fabris, L. Gregoratti, L. Aballe, P. Dudin, S. Baroni, and M. Kiskinova
Defect-controlled transport properties of metallic atoms along carbon nanotube surfaces
Phys. Rev. Lett. 99, 046803 (2007)

Adsorption of C60 on metal surfaces: formation of nanodimples and complex reconstructions
(Min Huang and Stefano Fabris)

The adsorption of organic molecules on metal surfaces can lead to complex nano-structuration of the supporting substrate. We unveils the precise atomistic and electronic structures of the C60/Au(110) interface by combining synchrotron-based diffraction and spectroscopic techniques with density functional theory calculations. The interaction between C60 molecules with Au(110) surface induces a massive interface reorganization leading to the Au(110)-p(6x5) substrate reconstruction and to the formation of surface nanodimples. The fullerenes are hosted by these nanodimples, which are one- and two-layers deep. The larger contact area between the C60 and the metal, resulting from the substrate rearrangement, allows for the formation of strong directional C-Au bonds.

In collaboration with:

  • ELETTRA and INFM-CNR TASC (M. Pedio)
  • Institut de Ciència de Materials de Barcelona (M. Hinterstein and X. Torrelles)
  • European Synchortron Radiation Facility (R. Felici)

M. Hinterstein, X. Torrelles, R. Felici, J. Rius, M. Huang, S. Fabris, H. Fuess and M. Pedio,
Looking underneath fullerenes on Au(110): Formation of dimples in the substrate,
Phys. Rev. B 77, 153412 (2008)

Fullerene adsorption on Rh surfaces
(Hande Ustunel, Stefano Fabris, and Stefano Baroni)

The chemisorption of fullerenes on metal surfaces typically involve hybridization between the molecular orbitals of C60 and the metal states near the Fermi level with reorganization of the charge at the interface. In the case of noble metal surfaces, this will often drive the chemisorbed molecular layer into a metallic state. We study the electronic structure of the fullerenes interacting with a Rh(110) surface by combining photoemission spectroscopy and density functional theory calculations.


In collaboration with:

  • ELETTRA - SuperEsca beamline (S. Lizzit, L. Petaccia, and A. Goldoni)