Sputtering and reflection processes from amorphous lithium surfaces by low-energy impacts of H and D atoms and D₂ molecules

This work presents a computational study of the retention, reflection, and sputtering processes at amorphous and crystalline lithium surfaces by the impact of low energy (5-100 eV) hydrogen and deuterium atoms and D₂ molecules for a range of incident angles of 0° (normal to the surface) to 85°. Classical molecular dynamics simulations were performed with the reactive bond-order force field (ReaxFF) potentials. Effects of the temperature of the surface slab were also considered. The extent of retention, and the energy and angular distributions of reflected and sputtered atoms were determined. Comparison of the results of these simulations with available experimental data on the sputtering rate for Li atoms is in good agreement for incident angles of 0°, and the simulation results predict significant increase in the sputtering probabilities for incident angles larger than 30°.