Study of dose effects on Au–Ni bilayers mixing by 300 keV Kr ions

Abstract

In order to study ion-beam induced mixing mechanism of immiscible system, Au/Ni bilayer systems were irradiated by 300 keV 84Kr 2+ ions at a number of ion doses ranging from 1 × 10 14 to 5 × 10 16 ions/cm 2. A series of Au(40 nm)/Ni(30 nm) bilayer samples were deposited on cleaned Si(1 0 0) substrates using dc magnetron sputtering in Ar atmosphere at a pressure of 5 × 10 −3 mbar. Distributions of different species after irradiation and post irradiation annealing were monitored by RBS technique using 2.05 MeV He 2+ beam. Mixing rate was determined as a function of ion doses using RBS spectra. With increasing doses, particularly at higher annealing temperatures, RBS spectra show a tendency to form metastable solid solution at Ni–Au interface. Discrepancy of the theoretical and experimental values of observed mixing rate has been explained by the existing models.