LOW-TEMPERATURE MIXING IN CU/W SUPERLATTICES IRRADIATED WITH LIGHT AND HEAVY-IONS

Ion irradiation effects, induced at low temperature in Cu/W superlattices prepared by ion sputtering, were studied and compared using in situ resistivity measurements and x-ray diffraction. The influence of the particle mass was particularly investigated in order to measure the role of spike effects in this immiscible system. It is shown that a more important mixing can be obtained with light-ion irradiation. Nevertheless, the contribution of ''thermally'' activated jumps opposing ballistic effects is significant even when small and weakly energetic cascades are formed. A dependence of the microstructural state and of the compositional substructure on the irradiating particle is also evidenced. Light-ion irradiation favors grain growth, restores grain texture, and preserves the composition modulation.