X-ray Photoelectron Spectroscopy (XPS)
The XPS, because of its versatility, is the most commonly used technique inside of the GCM to perform chemical analyses. In practice, this method can be used to quantitatively determine the elemental and molecular composition of samples. For example, it can measure the iron concentration in a sample but also determine the compound present (ex: Fe2O3).
This ultra-high vacuum techniques (UHV) analyses photoelectron emitted by a samples after being irradiated by magnesium or aluminum x-rays, as predicted by Einstein’s photoelectric effect.
Type of samples: organic or inorganic solids
Type of information obtained: elemental and molecular
Detection limit: 0.1 atomic %
Depth of analysis: 10 nanometers
Area measured: 2 mm x 3 mm
Quantitative and non-destructive analysis of organic and inorganic materials.
Identification of contaminants
Identification of molecules
Quantitative elemental and molecular analysis
Surface analysis (10 nm)
All types of materials (organic, inorganic)
Analysis in vacuum
Surface sensitive (possible contamination)
-Chemical composition and identification of minerals, alloys, polymers, industrial residues, etc…
-Failure analysis of paints, glues, construction materials.
-Analysis of corrosion and contamination products
Elements detected : Lithium – uranium
Resolution/sensitivity: 0.1 – 1 at%
Depth resolution : 1 – 10 nm
Lateral resolution : 2 mm
Other characteristics :
Temperature= -196 – 600o C,
Coating and preparation chamber (sputtering or evaporation)
Manufacturer: VG Scientific
Model : ESCALAB 3 MKII
Model : Axis Ultra