X-ray photoelectron spectroscopy of the effects of Ar+ ion sputtering on the nature of some standard compounds of Zn, Cr, and Fe

Highlights: • XPS study of influence of argon ion sputtering on possible ZnCr corrosions products. • Systematic investigation on powder references better reflecting real corrosion. • Only few reference materials show chemical stability. • Observed changes are mostly due to reduction taking place. • Combined results serve to assess the reliability of depth profiles acquired by XPS. - Abstract: X-ray photoelectron spectroscopy combined with Ar+ ion etching is a powerful technique for identifying the different chemical states of compounds in depth profiles to obtain information about buried regions beneath surfaces. The possibility of sputter damage is known but has been insufficiently investigated in the case of corrosion products of Zn-based steel coatings such as ZnCr. Thus, in this work, reference materials were studied according to their stability against ion sputtering. Indeed, some of the investigated compounds exhibited a highly unstable chemical nature. On the basis of these findings, the reliability of depth profiles of real samples can be rated