Self sputtering yields of silver under bombardment with polyatomic projectiles

Molecular dynamics (MD) have been employed to model self sputtering yields of an Ag(1 1 1) surface under bombardment with Agm (m = 1, 2, 3, 4) projectiles. It is shown that the effect of projectile orientation on the sputter yield decreases strongly with increasing m and becomes practically negligible under Ag4 impact. For polyatomic projectiles we observe a nonlinear yield enhancement which is discussed in terms of the collisional spike model of Sigmund and Claussen. It is shown that the MD simulation provides a unique method to determine the essential input parameters T0 and 〈ρ02〉 entering that model.