Use of Auger Parameter in the Characterization of Chemical State by X-ray Photoelectron Spectroscopy: A Review

In this review the concept of Auger parameter and its applications for the XPS analysis of materials and their surfaces are described. First, the definition of the Auger parameter and the experimental methods to obtain the Auger parameter are introduced. Then the physical meaning of the Auger parameter is clarified and the relations between the bulk properties of materials, such as polarizability, refractive index, and band-gap, and the Auger parameter is interpreted. The recent applications of Auger parameter for the analysis of materials and their surfaces, such as alloys, thin films, surface layers, clusters, catalysis, and surface corrosion, are reviewed.