Vibrational States Of Tetrahedral Amorphous Carbon

High resolution electron energy loss spectroscopy was used to observe variations in the vibrational states of amorphous carbon films with differences in preparation methods. Diamondlike films made by pulsed laser deposition (PLD) exhibit differences in the weighted phonon density of states relative to sputtered films. These differences are due to an increase of fourfold bonded atoms in the PLD films and are in qualitative agreement with theoretical calculations for amorphous carbon networks. (C) 1996 American Institute of Physics.