On Universality in Sputtering Yields Due to Cluster Bombardment.
Molecular dynamics simulations, in which atomic and molecular solids are bombarded by Arn (n = 60-2953) clusters, are used to explain the physics that underlie the "universal relation" of the sputtering yield Y per cluster atom versus incident energy E per cluster atom (Y/n vs E/n). We show that a better representation to unify the results is Y/(E/U0) versus (E/U0)/n, where U0 is the sample cohesive energy per atom or molecular equivalent, and the yield Y is given in the units of atoms or molecular equivalents for atomistic and molecular solids, respectively. In addition, we identified a synergistic cluster effect. Specifically, for a given (E/U0)/n value, larger clusters produce larger yields than the yields that are only proportional to the cluster size n or equivalently to the scaled energy E/U0. This synergistic effect can be described in the high (E/U0)/n regime as scaling of Y with (E/U0)(α), where α > 1.
†Department of Chemistry, 104 Chemistry Building, Penn State University, University Park, Pennsylvania 16802, United States.
Robert J
RJ
Paruch
†Department of Chemistry, 104 Chemistry Building, Penn State University, University Park, Pennsylvania 16802, United States.
Barbara J
BJ
Garrison
‡Smoluchowski Institute of Physics, Jagiellonian University, ulica Reymonta 4, 30-059 Krakow, Poland.
Maksymilian
M
Mlynek
‡Smoluchowski Institute of Physics, Jagiellonian University, ulica Reymonta 4, 30-059 Krakow, Poland.
Zbigniew
Z
Postawa
cluster sputtering; molecular dynamics; secondary ion mass spectrometry