Surface Deposition and Imaging of Large Ag Clusters Formed in He Droplets

TL;DR

This study uses transmission electron microscopy to analyze the size, deposition process, and stability of large silver clusters formed in helium droplets, providing insights into their surface assembly and growth dynamics.

Contribution

It demonstrates the use of a continuous helium droplet beam for controlled deposition of large Ag clusters and compares observed sizes with theoretical energy balance estimates.

Findings

Average cluster sizes match energy balance predictions

High probability of cluster attachment upon impact

Clusters remain stable on amorphous carbon substrates

Abstract

The utility of a continuous beam of He droplets for the assembly and surface deposition of Ag clusters, <N(Ag)> ~ 300 - 6 000, is studied with transmission electron microscopy. Images of the clusters on amorphous carbon substrates obtained at short deposition times have provided for a measure of the size distribution of the metal clusters. The average sizes of the deposited clusters are in good agreement with an energy balance based estimate of Ag cluster growth in He droplets. Measurements of the deposition rate indicate that upon impact with the surface the He-embedded cluster is attached with high probability. The stability of the deposited clusters on the substrate is discussed.