Surface segregated layer and native oxide layer formed on high-purity iron base alloys by angle-resolved XPS

An attempt has been made to describe recent views on segregated layers and native oxide layers formed on the surface of high-purity iron based alloys by applying angle-resolved x-ray photoelectron spectroscopy (AR-XPS). It is worth mentioning that AR-XPS is suitable for characterizing thin surface layers non-destructively, since thier thickness is nanometer order of magnitude, being comparable to inelastic mean free paths of X-ray photodectrons. This overview focuses the results on surface segregated layers of alloying and impurity elements such as chromium, phosphorus and sulfur in those alloys. It is also indicated that the amount of surface segregated chromium considerably affects formation of a native oxide layer in iron base alloys.