Oberflächenreichtum

Oberflächenreichtum refers to the phenomenon where the composition of the surface of a material differs from its bulk composition. This can occur due to various factors, including segregation of specific elements to the surface, adsorption of species from the surrounding environment, or chemical reactions occurring at the surface. The degree of surface enrichment is quantified by the surface excess, which is the difference between the surface concentration and the bulk concentration of a component, normalized by the surface area. Surface enrichment is a crucial aspect in many scientific and industrial applications, influencing properties such as catalysis, corrosion, adhesion, and electronic behavior. Techniques like Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS) are commonly employed to investigate and quantify surface enrichment. Understanding and controlling Oberflächenreichtum is essential for optimizing material performance and designing new materials with tailored surface properties. For instance, in catalysis, a specific component enriched on the surface might be the active site for a chemical reaction. Conversely, undesirable surface enrichment can lead to corrosion or reduced mechanical strength.