ELECTRONIC AND ATOMIC-STRUCTURE OF EVAPORATED CARBON-FILMS

Carbon films have been prepared at different substrate temperatures (2 5-800 degrees C) by evaporating carbon from a graphite source with an electron beam evaporation device. The films have been analyzed by in s itu electron spectroscopy (UPS, XPS and EELS), ex situ scanning tunnel ing microscopy (STM) and Raman spectroscopy. The UPS valence band and EELS spectra reveal a gradual transition from a disordered carbon film at room temperature deposition to a polycrystalline graphite-like fil m at 800 degrees C substrate temperature deposition, in good agreement with the results obtained from Raman spectroscopy. STM images of film s deposited at 25 degrees C also exhibit a rather disordered carbon ne twork, whereas with increasing substrate temperature, graphite nanocry stallites with sizes of about 20 nm are formed. A correlation between these different characterization techniques is performed.