Quantitative evaluation of sp/sp2 hybridization ratio in cluster-assembled carbon films by in situ near edge X-ray absorption fine structure spectroscopy

We present a near edge X-ray absorption fine structure spectroscopy characterization of nanostructured carbon films containing carbynoid species. By a careful data analysis and normalization of the spectra at the carbon K-edge we have quantitatively evaluated the extent of valence sp hybridization of the films. A sp/sp2 ratio between 10% and 25% has been obtained. This result allowed the evaluation of the ratio between the sp and sp2 Raman cross section at different excitation laser wavelengths.