Depth profiling of oxidized surface of stainless steels by synchrotron radiation excited X-ray photoelectron spectroscopy

Esaka, Fumitaka  ; Yamamoto, Hiroyuki; Sasase, Masato*; Magara, Masaaki  ; Shinohara, Nobuo 

In the present study, synchrotron radiation excited XPS (SR-XPS) is used to the analysis of surface oxides of stainless steels for obtaining information on surface composition in detail. Here, non-destructive depth profiling was performed by obtaining XPS spectra with different excitation X-ray energies. By oxidation at 200 C, significant change of the ratio was observed, indicating the enrichment of iron oxide on the surface at an initial stage of oxidation. With increasing oxidation temperature, enrichment of chromium oxide on the surface proceeded. No significant change with photon energy was observed for the sample oxidized at 400-800 C. These results imply that SR-XPS becomes a powerful tool for chemical state analysis of materials owing to the ability of non-destructive depth profiling.