Thickness determination of corrosion layers on iron using XPS depth profiling

Abstract

The study deals with the methodology and thickness determination of the corrosion layers of ferritic steel samples using X-ray photoelectron spectroscopy (XPS) equipped with the ion-gun source system enabling destructive depth profiling. It is well known that XPS is one of the most often used techniques for determining both the thickness and chemical composition of passive films or corrosive layers. Unfortunately, the thickness of ion-gun-etched layers can only be estimated for simple samples and standards. Corrosion layers are heterogeneous and vary in composition; therefore, the etching rate is specific for each corrosion layer. The results of this work provide the possibility for a fast and easy determination of the ion-gun sputtering effect with exact settings for multi-compound chemical structures. The knowledge related to the thickness of corrosion or passivation layers would help greatly in their characterization.