Influence of discharge power on the size of the Pd cluster generated with a magnetron plasma gas aggregation cluster source

Abstract Pd clusters were generated with a DC magnetron plasma gas aggregation cluster source. The dependence of the size distribution and ionization degree of the Pd clusters on the discharge power was studied. By tuning the discharge power from 15W to 50W, the mean size of the Pd clusters decreased from 13.8 nm to 4.2 nm, and the ratio of neutral and charged Pd clusters to the total rose from about 16.7% to about 76.7%. The effect was explained with a model by considering the enhanced production of Pd ions at higher magnetron discharge power. A simulation based on Direct Simulation Monte Carlo (DSMC) method verified the proposed mechanism of cluster growth.