Induced nucleation of diamond powder

Abstract

The effects of heteroatom addition on the nucleation of solid carbon in a low-pressure plasma reactor were investigated. Silane or diborane were added to acetylene mixed in hydrogen or argon. Oxygen was added to some of the diborane containing gas mixtures. Silane containing mixtures resulted in powder comprised of weakly bonded amorphous hydrogenated carbon-silicon material. The addition of diborane resulted in substantial production of diamond particles, 5 to 450 nm in diameter, under the conditions that show no diamond formation without diborane present. The observed yield of the oxidation-resistant powder produced in boron-containing mixtures reached 1.3 mg/h with the linear growth rates of diamond particles on the order of 102–104 μm/h. Implication of these results to interstellar dust formation is discussed.