Low Energy Ion Scattering Spectroscopy (LEIS/ISS)
A highly surface sensitive spectroscopy which compliments the chemical and quantitative analysis offered by XPS.
Ion Scattering Spectroscopy (also known as ISS or LEIS) is a technique whereby a monoenergetic beam of He+ or Ar+ ions are scattered by the atoms in a surface.
The loss of kinetic energy due to scattering caused by the mass difference between ion and scattering atom is measured and a spectrum is produced. Clearly two atoms in a surface which have very different masses (for example, oxygen and iron) will scatter ions differently.
More information on ISS can be found at:
Benefits
Applications
- detection of top-most surface elements
- determination of the relative surface coverage of a given element.
- adsorption on single crystal materials
- indication of monolayer surface coverage (e.g. by a self-assembled monolayer)
- growth of ultra-thin layers such as those produced by atomic layer deposition (ALD).
Availability
Systems at Harwell (all), Cardiff (Ultra) and UCL (Theta Probe) are equipped with ISS.