La Trobe University > Research > Research centres and institutes > Centre for Materials and Surface Science > Capabilities and facilities > X-ray Photoelectron Spectroscopy (XPS)

X-ray Photoelectron Spectroscopy (XPS)

X-ray photoelectron spectroscopy (XPS) is a surface-sensitive analytical technique, probing the first 5–10 nm of a sample surface and providing both elemental and chemical-state information. Today, it is used routinely in both research and industry to investigate surface-related phenomena.

Technique

In a typical XPS experiment, the sample is irradiated, under ultra-high vacuum, by soft X-rays of known energy (1–2 keV). This results in the photoemission of electrons from atoms in the sample, the kinetic energies of which are measured by the spectrometer. These energies identify the elements present in the sample surface and can provide information on their chemical states.

XPS is able to detect all elements, except hydrogen and helium, and provides a semi-quantitative measure of their relative concentrations.

Instruments

Kratos AXIS Ultra DLD

Kratos Axis Ultra
  • Spectroscopy and small-spot analysis.
  • Imaging.
  • Depth profiling using angle-resolved analysis or argon-ion etching.
  • Monochromated Al Kα or dual Mg/Al Kα X-ray sources.
  • Charge compensation for analysing insulating samples.
  • Kratos Axis Ultra
  • Sample heating and cooling.
  • In-vacuum sample cleavage.
  • Reaction chamber for gas dosing.
  • Glove-box for inert-atmosphere sample preparation, mounting, and transfer.
  • Remote-access operation.
Kratos Axis Ultra

Kratos AXIS Nova

Kratos Axis Nova
  • Spectroscopy and small-spot analysis.
  • Imaging, including stage raster for large-area mapping (up to 5 mm × 5 mm).
  • Depth profiling using angle-resolved analysis or argon-ion etching (with sample rotation).
  • Monochromated Al Kα X-ray source.
  • Charge compensation for analysing insulating samples.
  • Kratos Axis Nova
  • Large sample capacity for automated high-volume operation.