Nanoparticle Formation by Spark Discharge in Ar: Analysis of the Involved Mechanisms
Résumé
Nanoparticles are efficiently produced by using plasma sources such spark and/or arc discharges*. The major advantage of this technique is in the possibility of using several discharges in parallel to increase the yield of particles. To better control over this process, numerical study of the mechanisms involved is required. Herein, we present the results of a detailed numerical modelling performed for copper. The model consists of several parts: (i) first, we consider streamer formation and propagation for a short gap spark discharge in Ar at atmospheric pressure. In this part, we investigate ionization kinetics and energy balance; (ii) as soon as a breakdown occurs, we investigate the heating of the electrodes and compare the evaporation flow with the amount of sputtered copper atoms; (iii) finally, we compare the amount of nanoparticles formed by nucleation with the number of particles formed due to ion bombardment. The calculation results agree with the available experimental findings and help us to elucidate general trends and to connect them with the involved mechanisms. The performed analysis shows how the experimental conditions are correlated with the resulted properties of nanoparticles. *EU project BUONAPART-E www.buonapart-e.eu