Thermal spike analysis of interface mixing induced by swift heavy ions

Interface mixing induced by energetic ions is discussed, applying the author's thermal spike model. Diffusion in the ion-induced melt is assumed. An expression is derived for the variation of the mixing rate k with the electronic stopping power Se. The experimental results recently reported by the Stuttgart group on NiO, ZnO, CuO, and Cu2O layers on SiO2 substrate are analyzed and good agreement is found with the predictions of the model for k and for the threshold of Se for melt formation. Average diffusion coefficients in the spike are estimated, and Dd≅0.053, 0.03, and 0.004 cm2/s are obtained for Zn, Ni, and Cu ions, respectively