Published online by Cambridge University Press: 03 March 2011
The influence of the ambient atmosphere on the synthesis of diamond by chemical vapor deposition using an oxygen-acetylene torch is investigated experimentally. Diamond synthesis in an air atmosphere is compared to that in an inert atmosphere. It is found that the quality of diamond deposited on substrates positioned in the burnt gases near the premixed flame of the torch (within 1 mm) is independent of the composition of the ambient gas. Farther downstream from the premixed flame in the feather region, however, diamond deposition is controlled by the combustion of incomplete products from the premixed flame with oxygen from the atmosphere. In this region diamond grows in an annulus on the substrate with an air atmosphere, but no film is grown with an inert atmosphere.