Institut des
NanoSciences de Paris
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Low-dimensional oxides

UHV surface characterization experimental set-up

Contacts : Rémi Lazzari, Greg Cabailh, Jacques Jupille

 

Two ultrahigh vacuum set-ups of surface preparation and characterization techniques are available in the group. They are each divided into two chambers : preparation and analysis. The characterization techniques include :

  • Two ultra-high vacuum VT-SPM Omicron microscopes. They allow us to image and study the electronic properties of surfaces down to the atomic scale in tunneling current mode (STM, topography and spectroscopy) or in atomic force mode (contact and non-contact AFM). They are controlled by the Matrix version of the Omicron electronics or by the Scala one.
  • A heating stage and a He cryostat provide access to a range of temperatures from 30K to 800K in imaging conditions. The chamber containing the head of the microscope can accommodate evaporation cells in direct line of sight of the sample.
  • An Omicron EA125 photoelectron and ion analyzer. Several excitation sources can be used :
    • X-ray sources (XPS or PhD)
    • UV source (UPS)
    • Ion source (LEIS)
  • A SPECS 1D-delay line photoelectron analyzer with an dual anode x-ray source.
  • A low energy electron diffractometer (LEED)
  • A reflection high-energy electron diffractometer (RHEED)

In the analysis chamber, a 5-axis motorized UHV-design manipulator provides access to a range of temperature from 30K to 1200K. The preparation chamber includes :

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  • an electron bombardment annealing stage (1500K) ;
  • a 5-axis motorized UHV-design manipulator provides access to a range of temperature from 100K to 1500K ;
  • an ion gun (0.1-3keV) to bombard the surfaces ;
  • electron bombardment evaporators ;
  • a quartz microbalance ;
  • a load-lock system for fast introduction ;
  • a mass spectrometer ;
  • a gas ramp ;
  • a chamber designed for high pressure exposures (p>10-4mbar).

The UHV systems are equipped with pumping and bake-out systems as well as various pressure gauges. All transfers are compatible with Omicron sample plates. An UV-visible differential reflectivity spectroscopy experiment (200-1100nm) allows in situ monitoring of evaporation or exposure to gas. A software ’GranFilm’ was developed to calculate the Fresnel coefficients for layers of nanoparticles.