In X-ray Photoelectron Spectroscopy (XPS), a sample is irradiated by monochromatic X-rays under ultrahigh-vacuum conditions.  Photoelectrons are ejected from various atomic shells with characteristic kinetic energy, which gives their binding energy.
The presence of peaks at particular energies therefore indicates the presence of a specific element in the sample under study. The intensity of the peaks is related to the concentration of the element within the sampled region. Thus, the technique is capable of yielding a quantitative analysis.

 

Visit the Surface Analysis Facility

The HCRG routinely uses XPS to determine:

-Oxidation state(s)
-Changes in local chemical environment
-Surface compositions

Additional capabilities include:

-Inert atmosphere sample transfer
-Ar ion etching
-Depth profiling
-Angle resolved XPS

XPS spectra showing deconvoluted Mo3d region. 
Ni-Mo-Al catalyst reduced 500°C.