Quantification problems in depth profiling of PWR steels using Ar + ion sputtering and XPS analysis

    Research outputpeer-review


    The oxide scales of AISI 304 formed in boric acid solutions at 300°C and pH = 4.5 have been studied using X-ray photoelectron spectroscopy (XPS) depth profiling. The present focus is depth profile quantification both in depth and chemical composition on a molecular level. The roughness of the samples is studied by atomic force microscopy before and after sputtering, and the erosion rate is determined by measuring the crater depth with a surface profilometer and vertical scanning interferometry. The resulting roughness (20-30 nm), being an order of magnitude lower than the crater depth (0.2-0.5 μm), allows layer-by-layer profiling, although the ion-induced effects result in an uncertainty of the depth calibration of a factor of 2. The XPS spectrum deconvolution and data evaluation applying target factor analysis allows chemical speciation on a molecular level. The elemental distribution as a function of the sputtering time is obtained, and the formation of two layers is observed-one hydroxide (mainly iron-nickel based) on top and a second one deeper, mainly consisting of iron-chromium oxides.

    Original languageEnglish
    Pages (from-to)432-437
    Number of pages6
    JournalMicroscopy and Microanalysis
    Issue number5
    StatePublished - Oct 2006

    ASJC Scopus subject areas

    • Instrumentation

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