Composites from valence band features

The valence-region uv photoelectron spectrum of pyrite shows an intense peak at low binding energy arising from the six spin-paired electrons in the 2g levels (Fig. 6.11). Less pronounced features arise from the other valence-band electrons. The photoelectron spectrum can be aligned with x-ray emission spectra using more deeply buried core orbitals and, as shown from Fig. 6.11, provide further experimental data on the composition of the valence region. Thus, the Fe (5 spectrum shows the contri bution from orbitals that are predominantly Fe 4p in character, the S p... 

Valence-band spectra in XPS can be especially valuable in the study of fibers and composites because the analysis of such spectra may be able to assist in the interpretation of ambiguous spectral features in the core regions. The effects of achromatic x-radiation are also much less obvious in valcnce-band spectra for the reasons discussed in Section 5.4. With the help of the valence-band spectrum it is possible to distinguish between unfunctionalized hydrocarbons (47), while useful information about polymers can also be extracted. l). When comparing valence-band data with calculation, background and X-ray satellite removal from the experimental data is usually helpful, and can be performed effectively by data processing methods 129-31. ... 

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