It is almost always the case that the surface composition and chemistry of materials, measured on the order of a few atomic layers (~10 nm), is different from the 'bulk' composition determined by methods such as energy dispersive spectrometry (EDS) with excitation volumes that can extend as much as 3 microns into the material.įundamental Principles of X-Ray Photoelectron Spectroscopy XPS is used to support research on surface-mediated processes such as sorption, catalysis, redox, dissolution/precipitation, corrosion, and evaporation/deposition type reactions.

XPS is used to characterize the surfaces of diverse materials such as inorganic compounds (minerals), semiconductors, organic compounds, and thin films and coatings on natural and engineered materials. XPS is routinely used to determine a) the composition of material surfaces (elemental identification), the relative abundances of these components on surfaces (semi-quantitative analysis), and c) the chemical state of polyvalent ions by measuring the binding energies of elements, which is related to the nature and strength of their chemical bonds.

X-ray photoelectron spectroscopy (XPS) is a surface sensitive, non-destructive technique used routinely to analyze the outermost ~10 nm (~30 atomic layers) of natural and engineered materials.