Thin Fe and Ta layers of 30-45 nm thickness, deposited via magnetron sputtering on Si (1 0 0) substrates, were bombarded at room temperature with 100 keV Ar1+ or Ar8+ or with 250 keV Xe1+ or Xe19+ ions in order to test the influence of the ion charge state on the surface sputtering and interface mixing. The samples were characterized by means of Rutherford backscattering at 0.9-3.0 MeV α-particle energy, time-of-flight elastic recoil detection analysis with a 53 MeV 127I10+ beam and atomic force microscopy. No influence of the charge state on the sputtering and athermal mixing rate was observed in the case of the Ta/Si system. However, in the case of the Fe/Si system, the ion charge was observed to have an influence on the mixing rate. © 2003 Elsevier Science B.V. All rights reserved.