Compositional changes induced by ion beam bombardment have been studie
d for a variety of multilayer structures by means of the computer code
TOPS-TUI, which has been developed to simulate the collisional transp
ort in polyatomic targets. In this code, the relocation cross-sections
are calculated via Monte Carlo simulation and are introduced into the
set of integro-differential equations to be solved numerically. These
equations describe the dynamic behaviour of the mixing processes in w
hich sputtering and relaxation are also been included. Different multi
layer structures based on Fe plus metals like Al, Ni and Zr are analys
ed. The distortion of the concentration profiles at the interfaces and
the width of the regions which attain the nominal composition are inv
estigated as a function of the fluence. The dependence of these magnit
udes on the nuclear deposition energy and the effective volume ratios
of the components is studied in more detail.