Recoil and Threshold Energies of Single Crystal Sputtering by Heavy Ions

Within the framework of the mechanism of many-body interaction of a low-energy ion (E0 = 15–60 eV) with the surface atoms in single crystals, the highest recoil energies En of atoms have been calculated by the molecular dynamics method using the long-range interaction potential. The dependences of the recoil energy on the bombardment energy, the incidence angle, and the crystallographic directions of the incident ion motion have been obtained, based on which the energy thresholds for sputtering of a number of metals with the bcc lattice have been determined. The dependence of the threshold sputtering energy Ethr on the surface bond energy Ebond of atoms, the crystal lattice constant a, and the crystal orientation relative to the direction of the initial ion motion has been established. It is shown that the threshold sputtering energy increases, all other things being equal, with a decrease in interatomic distances and decreases with a decrease in the surface bond energy determined by the metal sublimation energy.