Carbon nanomaterials were prepared by chemical vapor deposition (CVD) and h
ot-filament CVD (HF-CVD) methods. The substrates were silicon (100) and cop
per plates on which catalytic metal or metal-oxide thin films were coated b
y means of the cathodic are deposition technique. Ethylene gas was used as
a precursor. HF-CVD with a filament temperature of 1,000 degrees C yielded
a larger amount of carbon deposit at a lower furnace temperature of 600 deg
rees C. High-resolution microscopic observation revealed a variety of amorp
hous carbon nanomaterials, such as frost columns, coral beads, microcoils,
nanocoils, and amorphous nanotubes.