Synthesis of Nanoparticles of Different Morphology in a DC Discharge

The synthesis of nanoparticles in the plasma of a stratified DC gas discharge was carried out under typical gas discharge conditions, i.e., at room temperature and an argon pressure of 0.11 torr, with a discharge current of 2.5 mA. The particles were formed and grown due to the sputtering of a dielectric plasma concentrator, which was used for strata stabilization. The analysis of the material collected using double-sided carbon tape placed on the glass wall of the discharge tube was performed by scanning electron microscopy and X-ray energy-dispersive microanalysis after the experiments. Three distinctive groups of particles of different shape and size were found, i.e., smooth spherical nanoparticles with a size of 10-100 nm, the main group of smooth spherical and dumbbell-like particles with a size of 200-500 nm, and micron-sized particles of complex cauliflower-like shape. EDX microanalysis of the synthesized nanoparticles revealed that the particles mainly consist of C, O, and Si, which proves that they were formed from the sputtered material of the silicone dielectric concentrator. Analysis of the particles and plasma parameters was performed, and a probable mechanism for the formation of such particles is proposed.