Influences of additions of hydrogen and methane on the combustion synthesis of diamond films

Abstract

An experimental study has been conducted in order to elucidate influences of additions of hydrogen and methane on the combustion synthesis of diamond films. Differences between the flat flame and the conical flame are first examined, and it is reconfirmed that the velocity gradient is one of the dominant parameters in the combustion synthesis of diamond films. Additions of hydrogen and/or methane are examined on the growth rates of diamond films, crystal sizes, and morphology. These results are also confirmed by conducting the similar experiments with a welding torch, instead of the flat flame burner. It is found that an addition of hydrogen reduces the growth rate and crystal size, while that of methane enhances those although homogeneity of the diamond films is reduced.