Electron-energy-loss spectroscopy of mass-selected ion-beam-deposited diamondlike carbon

Abstract

Amorphous diamondlike carbon (DLC) filmsgrown by low‐energy mass‐selected ion‐beam deposition have been examined by electron‐energy‐loss spectroscopy(EELS).Filmsgrown using deposition energies of 50, 120, and 300 eV have been studied. For these deposition energies, all films exhibit similar EELS characteristics indicating a very high degree of sp 3 bonding. The bulk plasmon resonance is intermediate between that of graphite and that of diamond; however, the properties of the low‐energy‐loss spectra of the DLC films are more similar to those of diamond. The near‐K‐edge carbonEELS data from the films exhibit a π* feature which is much smaller than that of graphite or evaporated carbon. The use of previously proposed computational methods on the near‐K‐edge EELS data indicates that over 80% of the carbon atoms are sp 3 bonded. The size of the π* feature is larger for smaller plasmon energies, as expected. The present data are in accord with other analyses of similar films that indicate a broad (∼30–300 eV) energy window for diamondlike film formation.