Note: Production of silver nanoclusters using a Matrix-Assembly Cluster Source with a solid CO2 matrix.

Abstract

One of the main limitations to the application of clusters on applied areas is the limited production; therefore, it is of great interest to up scale cluster production while keeping good size control. The Matrix-Assembly Cluster Source is a new high flux cluster source, which exploits cluster formation inside a solid rare gas matrix that is sputtered by an ion beam. Clusters are formed and ejected in this process. Here we report the production of Ag clusters when the rare gas is replaced by CO2 for the matrix formation at 20 K. Size distributions were determined from scanning transmission electron microscopy analysis of samples with four different metal loadings, 4%, 8%, 14%, and 23% of Ag atoms to CO2 molecules, and two ion beam energies, 1 keV and 2 keV. Cluster mean size showed weak dependence on metal loading, being ≈80 atoms for the first three concentrations, whereas the change in ion beam energy has caused cluster mean size to shift from 86 to 160 atoms. The results are interpreted in terms of bonding energy between Ag and CO2 and compared to the rare gas (Ar) matrix.