Nucleation of oriented diamond films on nickel substrates
A seeding and multistep deposition process has been developed to nucleate and grow diamond films directly on Ni substrates in a hot filament chemical vapor deposition system. High quality diamond films have been deposited without graphite codeposition on both 〈100〉 oriented single-crystal Ni and polycrystalline Ni substrates. Both 〈100〉 and 〈111〉 oriented diamond nuclei have been observed depending upon the underlying substrate orientations. Molten metallic phases were found surrounding the diamond nuclei, and it is speculated that a liquid layer composed of nickel, carbon, and hydrogen also formed on the diamond surface during the growth. The oriented diamond is believed to have been achieved by the reorientation of seeded diamond particles into alignment with the Ni substrate due to interaction between the diamond and Ni lattices.