Influence of High-Energy C60 Ions on the Structure and Bonds of Carbon Coatings

The carbon films formed by accelerated C60 ion deposition are investigated by transmission electron microscopy and X-ray photoelectron spectroscopy. It is demonstrated that amorphous carbon films are formed at an ion-beam energy of 7 keV and a temperature of the substrate of 100–200°C. Substrate temperature increase to 300°C results in the formation of nanocomposite films consisting of graphite nanocrystals embedded in an amorphous carbon matrix. The presence of double- and triple-charged C60 ions with an energy of 14 and 21 keV respectively in the beam results in a decrease in the temperature of formation of the nanocomposite to 200°C. As the result of analysis of the data collected from various sample depths by X-ray photoelectron spectroscopy and Auger-electron spectroscopy, it is found that the sp3/sp2 ratio in the surface layers is higher than in the sample bulk, both in the case of a monoenergetic 7 keV beam, and in the presence of multicharged high-energy ions in the beam. If high-energy ions are present in the beam, then the sp3/sp2 ratio is higher and depends, in a complex way, on the temperature of deposition. The maximum amount of sp3 bonds in the surface layers is found at a temperature of deposition of 350°C and is equal to 88%. The water drop contact angle for this film is 96°, which is similar to the contact angle of the diamond surface.