Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8042494 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2013 | 5 Pages |
Abstract
We model the sputtering of a LiF crystal induced by swift-ion impact. The impinging ion creates a trail of doubly ionized F+ ions, while simultaneously the corresponding electrons are set free. Ions move according to molecular dynamics, while excited electrons are treated by a particle-in-cell scheme. We treat the recombination time of electrons as a free parameter in our model. We find that the energy distribution of sputtered ions consists of 2 groups: a low-energy group centered at <1Â eV, and a high-energy group at 7-8Â eV. Fast ions (mainly Li+) are emitted early; these charge the surface negatively. Later, larger cluster ions and also neutral LiF molecules are emitted. Emission occurs at low angles to the surface normal. A jet along the normal direction can be observed, which is due to the electric field building up at the track surface. With increasing recombination time, processes are colder; sputtering decreases and the non-thermal jet structure becomes stronger.
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
Yaroslav Cherednikov, Si Neng Sun, Herbert M. Urbassek,