REDISTRIBUTION OF ATOMS IN THE NEAR-SURFACE LAYER OF MULTIELEMENTAL SOLIDS RELATED TO VARIATIONS OF THE ION-BEAM PARAMETERS

The kinetics of the surface composition and the distribution profiles of components in the near-surface layer of multielemental materials af fected by ion bombardment are analyzed during the time between two ste ady-state regimes of sputtering after a sharp increase in the energy o r intensity of ion bombardment. The experimentally observed non-monoto nic time dependences of the surface composition initiated by sharp cha nges in the parameters of ion irradiation of multielemental materials are explained on the basis of preferential sputtering and component in terdiffusion. It is shown that the redistribution of components in the altered layer leads to non-monotonic variations of the surface compos ition during the transient period between two steady-state regimes of ion irradiation. Good qualitative agreement between theory and experim ent has been obtained after a process of interdiffusion very sensitive to the parameters of ion beam, was included. The conclusion is drawn that the perturbation of any ion-beam parameters that lead to changes in the sputtering rate and interdiffusion coefficient is related to th e redistribution of components in the altered layer.