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High resolution and symmetry resolved corelevel spectroscopy using soft xray undulator (invited) Rev. Sci.Core-level photoabsorption has been used to determine the sp 2 and sp 3 bonding content of nanocrystalline diamond thin films grown using C 60 or CH 4 precursors. The C͑1s͒ absorption spectra show clear bulk diamond excitonic and sp 3 features with little evidence of sp 2 bonding, while the Raman spectra measured from these same films are ambiguous and indeterminate. This result can be attributed to the local structure ͑near-neighbor bonding͒ sensitivity of core-level photoabsorption that is insensitive to domain size, unlike Raman spectroscopy.

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Nanocrystalline diamond films have been deposited using a microwave plasma consisting of argon, 2-10% hydrogen and a carbon precursor such as C6o or C&. It was found that it is possible to grow the diamond phase with both carbon precursors, although the hydrogen concentration in the plasma was 1-2 orders of magnitude lower than normally required in the absence of the argon. Auger electron spectroscopy, x-ray diffraction measurements and transmission electron microscopy indicate the films are predominantly composed of diamond. Surface roughness, as determined by atomic force microscopy and scanning electron microscopy indicate the nanocrystalline films grown in low hydrogen content plasmas grow exceptionally smooth (30-50 nm) to thicknesses of 10 pm. The smooth nanocrystalline films result in low friction coefficients (p=0.04-0.06) and low average wear rates as determined by pin-on-disk measurements.

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