On Universality in Sputtering Yields Due to Cluster Bombardment

Area of Science:

• Materials Science
• Physics
• Computational Chemistry

Background:

• Cluster-solid interactions are crucial for understanding sputtering phenomena.
• Existing models often struggle to unify sputtering yield data across different cluster sizes and energies.

Purpose of the Study:

• To investigate the physics behind the "universal relation" in cluster sputtering.
• To propose an improved representation for unifying sputtering yield data.
• To identify and characterize synergistic effects in cluster bombardment.

Main Methods:

• Utilizing molecular dynamics simulations to model the bombardment of atomic and molecular solids with Argon (Ar) clusters (n = 60-2953).
• Analyzing sputtering yield (Y) per cluster atom against incident energy (E) per cluster atom (Y/n vs E/n).
• Introducing cohesive energy (U0) for a refined analysis: Y/(E/U0) vs (E/U0)/n.

Main Results:

• A novel representation, Y/(E/U0) versus (E/U0)/n, provides a better unification of sputtering data.
• A synergistic cluster effect was identified: larger clusters yield disproportionately higher sputtering.
• This synergy scales as Y with (E/U0)(α) (where α > 1) in the high energy regime.

Conclusions:

• The proposed unified representation improves the description of sputtering yields across various cluster sizes and energies.
• The synergistic effect highlights the importance of cluster size in determining sputtering efficiency.
• Findings offer new insights into the fundamental physics of cluster-induced sputtering.