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F. Esaka, H. Shimada, M. Imamura, N. Matsubayashi, T. Sato, A. Nishijima, A. Kawana, H. Ichimura, T. Kikuchi, and K. Furuya
[HYOUMEN KAGAKU, Vol. 16(7), pp.428-433, 1995]
X-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) using synchrotron radiation were applied for the investigation of the surface oxidation of chromium nitride films which were prepared by cathode are ion plating method. The XPS analysis of the oxidized samples exhibited the presence of nitrogen-containing intermediates with N1s XPS peaks at higher binding energies than the nitride. In the N K-edge XAS spectra of the oxidized samples, a sharp peak assigned to 1s->pi* transition was observed at higher energy than the peak assigned to chromium nitride. The above results indicate that with replacement of the nitrogen in chromium nitride by oxygen the released nitrogen occupies the interstitial position in the chromium oxide matrix as molecular or atomic nitrogen. A part of the interstitial nitrogen in the chromium oxide matrix is evolved from the surface with further progress of oxidation. Oxynitride species, described as CrNxOy, are not likely formed during the course of the surface oxidation.