3. Application to surface characterization

The concept of surface is always difficult to define. In the case of a pure, perfectly prepared material, the surface can be considered as the region of the sample affected by the presence of an atmosphere, a medium or a vacuum. This very general but restrictive definition is used in specific fields (e.g. chemisorption, catalysis) where only high-resolution methods are used, generally under ultra-high vacuum. In the case of an industrial product, it is easy to see that its surface composition differs from its core composition to depths that are sometimes very great, requiring other means of investigation.

• Generally speaking, industrial surfaces are highly complex, because at each stage of the process, the characteristics are linked not only to the last tool used, but also to the preceding stages. Even on the basis of a simplified schematic...