ION-BEAM MIXING CALCULATION OF MULTILAYER SAMPLES

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.