Experimental and theoretical study of the conditions for the formation of carbon nanostructures in an arc discharge in helium, argon and nitrogen

Abstract

Experimental measurements and numerical simulation of plasma parameters of an electric arc discharge in helium, argon, and nitrogen media at pressures of 25 Torr were carried out. On the basis of a theoretical model and experimental data on the interelectrode distance and the rate of sputtering of the anode, the radial distribution of the gas temperature is calculated. The obtained distribution is consistent with measurements carried out using a probe with a thermocouple, and the residence times of the sputtered material in different temperature ranges are determined. The properties and morphology of soot synthesized on the chamber walls were investigated by HRTEM, XRD and TGA methods. It is shown that during an arc discharge in nitrogen, the maximum number of graphite structures arises as a result of a longer residence of the sputtered carbon particles arising in the process at temperatures of about 700 -1700°C.