The size of thermal spikes in xenon-irradiated Ag/Fe bilayers

Ag/Fe bilayers in which a submonolayer of ¹¹¹In had been deposited in the Fe layer at a distance of x=0–17 nm from the interface, were irradiated at 80 K with 450 keV Xe ions to a fluence of 3 and 6⋅ 10¹⁵ ions/cm². Perturbed Angular Correlation spectroscopy was used to monitor the microsurrounding of the ¹¹¹In tracers and to identify the radiation-induced defects. The fraction of tracer atoms being transported into the Ag layer cannot be explained by ballistic mixing, but is reproduced when assuming local thermal spikes to develop. The diffusion of ¹¹¹In into the Ag layer can be modeled if the local spikes have an average diameter of some 5 nm. This revised version was published online in August 2006 with corrections to the Cover Date.