The interaction of oxygen molecules with iron films studied with MIES, UPS and XPS

摘要

X-ray Photoelectron Spectroscopy (XPS), Metastable Induced Electron Spectroscopy (MIES) and UltravioletrnPhotoelectron Spectroscopy (UPS) were applied to study the interaction of oxygen molecules with iron films.rnSupplementarily, iron oxide was investigated for comparison.rnWith XPS from the Fe 2p_(3/2) range contributions of metallic Fe as well as Fe~(2+) and Fe~(3+) can be distinguished.rnDuring the interaction with oxygen an oxide film is formed on the iron surface. Nevertheless, XPS still showsrnmetallic contributions even for a surface which is saturated with more than 10~4 L. The oxide film hinders therndissociation of further impinging oxygen molecules.rnThe interaction of He~* atoms with iron oxide surfaces during MIES is dominated by Auger Neutralization.rnThis surprising result follows from the high work function and the fact that intrinsic defects result in a Fermirnlevel pinning to the conduction band.