ATOMIC TRANSPORT IN THERMAL SPIKE INDUCED ION MIXING

A simple relationship between the ratio of atomic transport induced by ion mixing and the activation energies for the impurity diffusion of constituents in a bilayer is presented to describe quantitatively the symmetric and asymmetric atomic transport in the thermal spike induced ion mixing. The model predicts fairly satisfactorily the trend of exp erimental observations in the bilayer systems which have near zero hea ts of mixing and relatively high spike activation energies. For instan ce, the Pd/Co bilayer system shows nearly symmetric atomic transport, since its constituents have similar activation energies for the impuri ty diffusion.