Ion Beam Mixing

Ion beam mixing is a phenomenon at interface between two layers, in which the atoms of one layer mingle with the atoms of the other elements under the influence of ion beam traversal through this. A low energy ion beam irradiation causes a ballistic mixing at the interface due to elastic collision cascades. The elastic collisions produce considerable defects in both the layers. These defects assist the diffusion across the interface, referred to as radiation enhanced diffusion. Since the energy lost by the ions in elastic collisions is called nuclear energy loss, therefore nuclear energy loss is considered to be responsible for ion beam mixing. It was later shown that the mixing at the interface could also be induced by the large electronic excitations of high energy heavy ions with the atoms in the sample. The striking feature of ion beam mixing is that (i) it has spatial selectivity, (ii) it is rather a low temperature process and (iii) thermodynamically immiscible systems, in principle, can be mixed.   


For a survey on electronic excitation induced ion beam mixing: download.