Enhancement of W Nanoparticles Synthesis by Injecting H2 in a Magnetron Sputtering Gas Aggregation Cluster Source Operated in Ar

Abstract

Synthesis of W nanoparticles by magnetron sputtering combined with gas aggregation operated in Ar suffers from a continuous decrease of the synthesis rate, ceasing in a finite time interval, in the range of minutes to tens of minutes. Experimentally, we noticed that adding small amounts of H2 to Ar (5–20%) increases the synthesis rate, which remains constant over time, at a value dependent on the amount of injected hydrogen. Mass spectrometry investigations revealed, in the hydrogen presence, a dominance of the ArH+ ions over the Ar+ ones, associated also with an increased number of W+ and WH+ species in plasma, sustaining a substantial increase in the nucleation rate.