NANOCRYSTALLITES IN TETRAHEDRAL AMORPHOUS-CARBON FILMS

The microstructure of filtered cathodic vacuum are deposited tetrahedr al amorphous carbon films is studied as a function of ion energy. An o ptimum energy window in the density and C-C sp(3) content at an ion en ergy of similar to 90 eV observed in this study. It is shown that the density of the amorphous carbon films are closely related to the sp co ntent. The observation of nanocrystals embedded in the amorphous carbo n matrix is reported. Most of the crystals observed by transmission el ectron microscopy can be indexed to graphite, but some of the crystals can be indexed to cubic diamond. The chemical composition of the crys tals is analyzed using electron energy loss spectroscopy (EELS), The o nly discernible EELS edge is that of C at an energy of 285 eV. (C) 199 6 American Institute of Physics.