EELS analysis of vacuum arc-deposited diamond-like films

Electron energy-loss spectroscopy measurements have been made on amorphous diamond-like carbon films produced by condensing the plasma stream from a filtered vacuum arc. The results are compared with spectra from diamond, graphitized carbon and amorphous carbon. Although the energy-loss spectra reveal the presence of a small quantity of sp2-bonded material in the diamond-like film, the high plasmon frequency and shape of the K-edge show that the material is essentially an amorphous form of diamond. The fraction of sp2- bonded carbon was quantified and found to be of the order of 15%. It was not possible to determine if the sp2 carbon was on the surface or throughout the bulk.