Binding energy effects in cascade evolution and sputtering

[摘要] The MARLOWE model was extended to include a binding energy dependent on the local crystalline order: atoms are bound less strongly to lattice sites near surfaces or damage. Sputtering and cascade evolution were studied in self-ion irradiations of Cu and Au monocrystals. In cascades, the mean binding energy is reduced similar to 8% in Cu with little dependence on the initial energy; in Au, it is reduced similar to 9% at 1 keV and similar to 15% at 100 keV. In sputtering, the mean binding energy is reduced similar to 8% in Cu and similar to 15% in Au with little energy dependence; the yields are increased less, averaging about half as much. Most sites from which atoms are sputtered are isolated in both metals. Small clusters of sites occur in Cu, but there are some large clusters in Au, especially in {111} targets. There are always more large clusters with damage-dependent binding than with a constant binding energy, but only a few clusters are compact enough to be regarded as pits.

[发布日期] 1996-07-01

[效力级别]  Proceedings Paper