GROWTH OF DIAMOND FILM BY A PLUG-FLOW FLAT FLAME METHOD

The conventional acetylene-oxygen mixture torch flame can grow diamond film at fast rates, but it suffers from problems such as small area coverage, non-uniform growth, and poor reproducibility due to the large concentration and temperature gradients. Considering the effects of momentum, heat and mass transfer in the flame, we proposed to study diamond growth by the plug-flow flat flame method. Our results indicated that, owing to the large burning velocity of the acetylene-oxygen mixture, dilution was required for reasonable gas consumption. The growth of uniform diamond films by a flat flame method was successful. Dilution, however, reduced the growth rate of diamond significantly and the crystal qualities deteriorated. The effects of dilution gases were studied by comparing nitrogen and argon. Argon was more favorable for diamond growth than nitrogen. The possible reasons will be discussed.