end of the 8 hours a continuous diamond coating was deposited on the nickel coated pyrolytic graphite substrate there were no voids present the diamond crystallite sizes ranged from submicron to one micron in diameter a graphite adhesive substrate was coated with 2500 u00e5 of nickel metal as described above the nickel metal coating was then diamond abraded with 0 0 25 micron diamond particles for 20 minutes and then wiped clean diamond deposition was carried out as in example 1 except that a 25 v bias was applied to the substrate stage at the end of the 8 hours a continuous diamond coating was deposited on the nickel coated graphite adhesive substrate there were no voids present the diamond crystallite sizes ranged from submicron to two microns in diameter raman spectra were taken of the diamond film and the graphite adhesive substrate the raman spectrum of the diamond showed a single peak at 1324 cm 1 which is consistent with highly stressed diamond since stresses in diamond can cause a shift to a lower wavenumber from the usual raman peak centered at 1332 cm 1 for polycrystalline diamond a section of the diamond film was removed and the portion.