Published online by Cambridge University Press: 22 February 2011
Radiation-induced segregation (RIS) in Ni-12.7% Si and Cu-1% Au alloys was studied using Rutherford backscattering spectroscopy during He and Ne irradiation at elevated temperatures. During single ion-beam irradiation with 1.5 MeV He, strong RIS of Si toward the surface was observed in Ni-12.7% Si. Simultaneous irradiation with 400 keV Ne and 1.5 MeV He almost completely suppressed the Si segregation, even when the calculated damage production rate by Ne was only a few percent of that by He ions. A similar effect of dual-beam irradiation was observed in the Cu-1% Au alloy, i.e., the rate of near surface Au depletion was strongly reduced under simultaneous irradiation. The present result shows that dual-beam irradiation can be applied to control RIS and RED (Radiation Enhanced Diffusion) during ion beam processing.