TY - JOUR
T1 - Molecular dynamics simulations of low-energy cluster deposition on metallic targets
AU - Pelletier, J. D.
AU - Shapiro, M. H.
AU - Tombrello, T. A.
N1 - Funding Information: Low-energy deposition of clusters may become an important new technique for producing epitaxial films at low temperature \[1\].T ombrello \[2\]h as pointed out the importance of molecular dynamics (MD) simulations to improve our understanding of this process, and to help guide future experimental work in this field. Only a few previous attempts have been made to simulate low-energy cluster deposition. Miiller \[3\]a nd Biswas, Grest, and Soukoolis \[4\]a ttempted MD simulations of film formation with very low energy clusters. Hsieh andl Averback \[5\],u sing an embedded-atom MD code, simulated one event each for 13-atom Cu clusters with energies of 3.54 and 25 eV/atom impacting a Cu target, and one event each for 92-atom Cu clusters with energies of 1 and 3.54 eV/atom impacting the same material. They found that the 25 eV/atom, 13-atom cluster produced a small crater, while the clusters with energies/atom less than or equal to the Cu binding energy (3.54 eV) produced epitaxial layers on the surface without creating point defects. Yamamura \[6\] used a Monte Carlo code to simulate the deposition of silver clusters on carbon, and found significant differ-enees bet~veen results from linear and nonlinear versions of the program. In order to understand more fully the processes of defect ptroduction, atomic mixing, implantation, and * Supported in part by NSF Grant DMR90-11230 at Caltech, and by NSF Grant DMR90-02532 at CSUF.
PY - 1992/4/1
Y1 - 1992/4/1
N2 - A modified version of the multiple interaction code SPUT2 was used to simulate impacts of 63-atom Al and Au clusters on 7-layer Au targets. For 1, 5, and 10 eV/atom Al and Au clusters, 50 impacts each were calculated up to a cutoff time of 2 ps. For each case studied, we found that the final shape and penetration depth of the incoming cluster was almost independent of the initial cluster position relative to the target. The 1 and 5 eV/atom Al clusters were flattened to less than 40% of their initial thickness and exhibited registration with the substrate at 2 ps. The 10 eV/atom Al clusters formed a poorly registered monolayer on the Au surface. In these higher-energy collisions a significant number of Al atoms were reflected from the Au surface. The 1 eV/atom Au clusters were flattened to approximately 60% of their initial thickness and also exhibited clear registration with the substrate at 2 ps. Higher-energy Au clusters penetrated deeply into the targets, causing substantial damage and crater formation.
AB - A modified version of the multiple interaction code SPUT2 was used to simulate impacts of 63-atom Al and Au clusters on 7-layer Au targets. For 1, 5, and 10 eV/atom Al and Au clusters, 50 impacts each were calculated up to a cutoff time of 2 ps. For each case studied, we found that the final shape and penetration depth of the incoming cluster was almost independent of the initial cluster position relative to the target. The 1 and 5 eV/atom Al clusters were flattened to less than 40% of their initial thickness and exhibited registration with the substrate at 2 ps. The 10 eV/atom Al clusters formed a poorly registered monolayer on the Au surface. In these higher-energy collisions a significant number of Al atoms were reflected from the Au surface. The 1 eV/atom Au clusters were flattened to approximately 60% of their initial thickness and also exhibited clear registration with the substrate at 2 ps. Higher-energy Au clusters penetrated deeply into the targets, causing substantial damage and crater formation.
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U2 - 10.1016/0168-583X(92)95820-H
DO - 10.1016/0168-583X(92)95820-H
M3 - Article
SN - 0168-583X
VL - 67
SP - 296
EP - 300
JO - Nuclear Inst. and Methods in Physics Research, B
JF - Nuclear Inst. and Methods in Physics Research, B
IS - 1-4
ER -