Effects of Gas Pressure on the Size Distribution and Structure of Carbon Nanoparticles Using Ar + CH4 Multi-Hollow Discharged Plasma Chemical Vapor Deposition∗)

Using an Ar + CH4 multi-hollow discharge plasma chemical vapor deposition (MHDPCVD) method, carbon nanoparticles (CNPs) are synthesized in a size range between 10 nm and 100 nm at gas pressures from 2 Torr to 5 Torr. The size of the nanoparticles increases from 45.42 nm3 at 2 Torr to 67.85 nm3 at 5 Torr. The size dispersion also increases. Conversely, the optical emission intensities and generation of carbon related radicals decrease with increasing pressure. The Raman measurements indicate that these CNPs are composed of polymer structures containing relatively high clustered and distorted sp2 sites.