X-ray Photoelectron Spectroscopy (XPS), also known as ESCA - Electron Spectroscopy for Chemical Analysis, is a non-destructive technique which provides chemical analysis of the outermost 5 – 10 nm of any vacuum compatible solid.  The sample is illuminated with monochromatic X-rays which have sufficient photon energy to cause the photoemission of the core level electrons whose binding energies are characteristic of the elements present.  The position and intensity of the peaks provide both chemical (e.g. oxidation state) and quantitative (> ~0.1 atom %) information for all elements except hydrogen.  Underlying layers can be examined by the use of XPS in conjunction with a gas cluster ion source (GCIS) providing elemental depth information due to the destructive nature of the ion bombardment.

The X-ray analysis facility is equipped with a state of the art Kratos AXIS Supra Plus XPS system which uses a dual monochromated Al Kα/Ag Lα X-ray source with the following capabilities:

•    Sample sizes up to 4cm in diameter and up to 20 mm thick
•    Load lock for fast sample interchange
•    Precision auto stage for multiple unattended sample analysis
•    Minibeam 6 GCIS for cleaning and depth profiling of multilayered thin films
•    Variable angle sample orientation- angular resolved XPS
•    Sample heating (up to 800 oC) and sample cooling (down to -150 oC)
•    Elemental imaging (min 200 µm x 200 µm) on selected samples, up to 5 µm spatial resolution
•    Small spot analysis  (min 27µm) on selected samples
•    Surface Science Station for dosing of gases
•    UPS lamp, He(I)- 21.22 eV
•    Casa XPS data processing software is available for use within the facility by all CMM members. 

Location: Chemistry Building

Contact: Dr Craig Stoppiello; c.stoppiello@uq.edu.au