Sputtering of Ag under C ₆₀ ⁺ and Ga ⁺ projectile bombardment

Cluster ion bombardment often results in large secondary ion yield enhancements relative to atomic ion bombardment. The yields of neutral particles and secondary ions sputtered from a silver surface were investigated through experiments and molecular dynamics (MD) computer simulations. The results show that the neutral Ag yield produced by 15keV C ₆₀ ⁺ bombardment is 5.6-fold higher than that found for 15keV Ga ⁺ bombardment, which is in agreement with simulations. The enhancement effect is observed to be about the same for both neutral species and their corresponding secondary ions. Experimental results also indicate that the Ag neutral species produced by C ₆₀ ⁺ bombardment have emission velocity distributions that maximize at much lower values than those observed by Ga ⁺ bombardment, suggesting the presence of non-linear collision cascades.