Growth and analysis of carbonaceous and metallic microparticles using capacitively coupled rf plasmas

This presentation reports on the formation of carbonaceous nanometer to micrometer sized particle formed in a capacitively coupled rf plasma using a mixture of argon and acetylene and/or metal-organic gaseous precursors. Experiments are performed using a 13.56 MHz rf source that delivers up to 10 W of input power to various gas mixture. Particles spontaneously grow in this plasma and form a dust cloud which levitates in between the electrodes. Particle growth is cyclic as particles grow large enough to no longer remain suspended in the plasma; leading to a subsequent growth process. Particle that fall out of the plasma are captured on a glass slide at the bottom of the experiment. Ex-situ analysis is performed on the particles to determine their size distribution and chemical composition. For the carbonaceous particles, optical microscopy images reveal that their average diameter increases from ~0.5 to ~0.9 μm with increasing acetylene flow rate. Upcoming experiments will examine the properties of the metallic particles. The long term goal of these studies is to fully characterize particle growth of a variety of particle types ahead of future experiments to study particle growth in strongly magnetized plasmas.