Abstract
A flame combustion method enables the synthesis of diamond using acetylene-oxygen in ambient atmosphere. It has various advantages over other methods. In this method, during cooling, most diamond films delaminate as a result of thermal stress. We previously synthesized diamond films on a Mo substrate surface by the flame combustion method. To prevent diamond film delamination for the synthesis of good diamond films, a three-step synthesis method was proposed. In this study, to reduce the surface roughness of diamond films and to achieve good adhesion on the Mo substrate, diamond films were synthesized by flame combustion with the three-step synthesis method. The diamond seed particles as growth nuclei for the diamond synthesis were changed to small. Furthermore, the flow ratio of oxygen flow rate to acetylene flow rate and synthesis time zone were carefully varied during the three-step synthesis method. To investigate the influence factors of the surface roughness of synthesized diamond films, synthesized films were observed. The diamond seed particles size, the flow ratio and synthesis time zone affected the surface roughness.
