ABSTRACT
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1.1 INTRODUCTION
Corrosion is traditionally subdivided into two main topics, high-temperature corro-
sion with the attack of solid surfaces by hot and aggressive gases and aqueous
corrosion with the degradation of materials in contact with aqueous electrolytes.
Even in the case of atmospheric corrosion the surface of materials is exposed to thin
electrolyte layers sometimes with successive wet and dry periods. Most important are
metal surfaces although corrosion may also happen to nonmetallic materials such
as semiconductors, insulators, and even polymers. The methods to study corrosion
depend decisively on the systems. Aqueous corrosion was traditionally a domain of
electrochemical research and various electrochemical methods have been applied to
the study of corrosion of metals in electrolytes. These methods provide a good
qualitative and quantitative insight. However an unambiguous interpretation of the
chemistry and kinetics as well as the mechanisms of the observed processes requires a
very detailed information on the surface of the materials and its changes. For these
reasons there exists a strong demand for the application of surface analytical methods.
X-ray photoelectron spectroscopy (XPS) is a very successful surface analytical tool
for corrosion research but also for the investigation of corrosion failures in industry,
related to various environments. Although XPS requires a sample transfer from the
electrolyte to the ultrahigh vacuum (UHV) with a loss of the contact to the electrolyte
and the control of the electrode potential, it provides reliable data on the chemical
situation of the surface. This information is required to get a sound base for the
interpretation of the mechanisms of corrosion processes and their kinetics.
