SAMOS

SAMOS

Giorgio Contini  -

SAMOS

 
The ultra-high-vacuum (UHV) apparatus at SAMOS Lab has been designed to investigate the structure and reactivity of surfaces with particular attention to organic molecules adsorbed on metal and semiconductor surfaces. Molecules can be deposited on the sample, previously treated to obtain a clean and reconstructed surface (by annealing and Ar ion sputtering facilities). Low energy electron diffraction (LEED) and mass spectrometer are used to control the samples. After the preparation, the samples can be transferred in the analysis chamber, equipped with a Al-Mg X-ray source, an electron gun and a five-channeltrons VG electron analyzer, were X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) can be done. The preparation and analysis chambers share the same manipulator. A fast entry lock and a supplementary chamber for samples treatments are present.
 
 

TECHNICAL SPECIFICATIONS

  • Al-Mg X-ray source
  • electron gun
  • five-channeltrons VG electron analyzer
  • preparation chamber
  • preparation chamber and analysis chamber share the same manipulator
  • fast entry lock and a supplementary chamber for samples treatments

AVAILABLE TECHNIQUES

  • XPS

  • LEED

  • EELS

 

SAMPLE

  • Solid samples: lateral dimensions 9 x 9 mm (ideal), 6 x 6 mm (minimal), 11 x 11 mm (maximal)

  • Sample thickness: ideally up to 2 mm (thicker samples also feasible)

  • Sufficient electrical conductivity of samples needed to avoid charging

 

USE FOR

  • Study of the surface of metals and semiconductors
  • Ultra-thin Films
  • Chemical reactions on surfaces
  • Catalysis
 
 

Case Studies

Two-dimensional π-conjugated polymers

Two-dimensional π-conjugated polymers constitute a promising subclass because the band structure can be manipulated by varying the molecular building blocks while preserving key features. The fabrication of mesoscale ordered two-dimensional π-conjugated polymer kagome lattices with semiconducting properties, Dirac cone structures and flat bands on Au(111) has been demostrated. These results open opportunities for the synthesis of two-dimensional π-conjugated polymer Dirac cone materials and their integration into devices.

See: G. Galeotti, ... e G. Contini, Nature Materials 2020, https://doi.org/10.1038/s41563-020-0682-z

 
 
 
 

Organometallic intermediate in surface-confined Ullmann coupling

Ullmann coupling is generally described as a two-step reaction: (i) dehalogenation, resulting in the formation of a stable intermediate organometallic phase and subsequent (ii) C–C coupling. The topology of the resulting polymer is determined by the structure of the intermediate phase. Hitherto, only one intermediate structure, identified as an organometallic (OM) phase, has been reported for such a reaction. Here we demonstrate the formation of two distinct OM phases during the temperature-induced growth of poly(para-phenylene) from 1,4-dibromobenzene precursors on Cu(110). This new intermediate phase, revealed only when the reaction is carried out at low molecular coverages, was characterized by X-ray photoelectron spectroscopy, scanning tunneling microscopy and near-edge X-ray absorption fine structure spectroscopy, and modeled by density functional theory calculations.

See: G. Galeotti, ... e G. Contini, Nanoscale, 2019, 11, 7682

 
 
We use cookies essential for the functioning of the site. You can decide for yourself whether or not to allow cookies. Please note that if you refuse them, you may not be able to use all of the site's features.