Evaporated palladium films of 45 nm thickness on Si(1 1 1) were irradiated using 78 keV Ar+ ions with doses in the range of 1×1015 to 1.5×1016 cm−2 for the purpose of studying silicide formation. Rutherford backscattering analysis shows that intermixing has occurred across the Pd-Si interface at room temperature. The mixing behaviour increases with increasing dose of the bombarding ions, which agrees well with a theoretical model of isotropic cascade mixing for palladium, and radiation-enhanced diffusion associated with an interstitial mechanism for silicon.