Potential Sputtering of Lithium Fluoride by Slow Multicharged Ions

Thin polycrystalline LiF films have been bombarded by slow $(\le 1$ keV) multicharged ${\mathrm{Ar}}^{q+}$ ions $\left(q\le 9\right)$, in order to study the resulting total sputter yields by means of a quartz crystal microbalance. More than 99% of sputtered particles are neutral and show yields, at given impact energy, in proportion to the potential energy of projectile ions. The respective “potential sputtering” process already takes place far below 100 eV impact energy. It can be related to defect production in LiF following electron capture by the multicharged ions, and removes about one LiF molecule per 100 eV of projectile potential energy.