A new approach to prepare diamond-like carbon film was made by highly accelerating ultra-fine carbon black particles between plane-parallel electrodes held at DC high voltage in 10-4 Torr, and by making the energetic particles deposit onto the surfaces of electrodes used as substrate. It became clear that amorphous hard carbon films grow only on cathode surface without heat generation and the growth rate depends on the rate of kinetic-energy flux given by the particles striking unit cathode area. The average growth rate of about 10 nm/min was obtained using a 180 mm dia. cathode with relatively low power supply. As for the properties of film prepared, the Vickers hardness value larger than 1 500 kgf/mm2 and the semiconductive hopping conduction were observed, which are quite different from carbon black used. These suggest that the graphitic starting material may be transformed into considerably disordered carbon structure due to severe solid-to-solid impact, and a diamond-like carbon film of graphite rich may be formed.
