THE INFLUENCE OF CATHODE SPUTTERING ON THE PROPERTIES OF DC GAS-DISCHARGE PLASMA
Abstract
This paper presents the results of an experimental study of the formation pro-
cesses and properties of plasma with nanoparticles under cathode sputtering. The experiments were
carried out in a DC gas discharge. We have investigated the regimes of combustion of a gas dis-
charge at low (1 mA) and large (1416 mA) discharge currents.
At high values of the discharge current, the hollow cathode is a source of fast electrons, as
well as eroded and adsorbed atoms and molecules. These processes are accompanied with cathode
sputtering. During cathode sputtering, the heat flux of atoms and molecules entering the volume of
the gas discharge, instantly coagulates and forms nanoparticles. In addition, due to the agglomera-
tion between the nanoparticles formed nanocluster. This is evidenced by the SEM images of nano-
particles (~120 nm) and nanoclusters (~500 nm). The obtained emission spectra of gas discharge
atoms shows that cathode erosion products in the gas discharge are present only in the form of na-
noparticles and nanoclusters. Thus, during cathode sputtering, the gas discharge is contaminated,
which leads to the formation of a complex plasma, that is, a gas discharge plasma with nanoparticles. It is revealed that the purity of the experiment depends on the adsorbed gas on the cathode sur-
face. It was found that the output of adsorbed gas from the cathode surface strongly affects the total
gas pressure in the discharge tube. In addition, a slight change in the pressure of the gas in the tube
is also possible with the presence of molecular nitrogen. Molecular nitrogen in a gas discharge with
a high current dissociates into atomic nitrogen, which leads to an increase in the total pressure in the
tube.
