Micro-crystalline diamond and nano-carbon structures produced using a highargon concentration in hot-filament chemical vapor deposition

Micro-crystalline diamond films and nano-carbon structures in the form of w ires have been grown by the introduction of argon at very high concentratio ns (60%-87.5% vol Ar) into the feed mixture (ethanol and hydrogen) of a hot -filament chemical vapor deposition reactor. The argon, in addition to acti ng as an inert diluent, also modified the kinetics of the carbon deposition process; its presence apparently minimized the deposition of intergranular hydrogenated species, induced an increase in the number of flaws between t he diamond grains, increased the porosity of the films, and formed new carb on structures. Well-faceted diamond films, diamond-like carbon (DLC) balls, spongy-like wires, and multilayer structures were observed at different co ncentrations of Ar. Raman spectroscopy of the deposited material showed tha t structures of high quality diamond (60%-65% vol Ar) and carbon structures related to DLC, fullerenes and carbon nanotubes, may be deposited by this process. (C) 2001 American Vacuum Society.