CHARACTERIZATION OF NANOCRYSTALLINE DIAMOND FILMS BY CORE-LEVEL PHOTOABSORPTION

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 CH4 precursors. The C(ls) absorption spectra show clear bulk d iamond excitonic and sp(3) features with little evidence of sp(2) bond ing, while the Raman spectra measured from these same films are ambigu ous and indeterminate. This result can be attributed to the local stru cture (near-neighbor bonding) sensitivity of core-level photoabsorptio n that is insensitive to domain size, unlike Raman spectroscopy. (C) 1 996 American Institute of Physics.