In this paper, we studied the effects of hydrogen gas flow ratio of [H2]/[N2 + CH4 + H2] on the quality of nanometer diamond (nano-diamond) films prepared by microwave plasma enhanced chemical vapor deposition method. Nano-diamond films were deposited on the silicon substrates from a gaseous mixture of nitrogen, methane and hydrogen. The experimental results show that if only using a gaseous mixture of nitrogen and methane, although we can obtain nano-diamond films with a grain size of about 5nm, the diamond films contain much non-diamond components. With hydrogen addition, and with increasing the hydrogen gas flow ratio from 1 to 10%, the non-diamond components in the films are significantly reduced and the grain size of the films increases from 5nm to 60nm. However optical transmittance of the films increases with increasing hydrogen gas flow ratio from 1 to 7% because of an improvement of film quality, and then decreases with further increasing hydrogen gas flow ratio owing to the increase of film roughness.
Effect of Differentiated Injection Ratio, Gas Flow Rate, and Slag Thickness on Mixing Time and Open Eye Area in Gas-Stirred Ladle Assisted by Physical Modeling