Effect of Projectile Energy, Specimen Temperature and Fast Thermal Diffusing Atoms on Ion Beam Mixing

Ion beam mixing of Au markers in Cu samples was measured after 500-keV Kr irradiation at 6, 80, and 295 K. Additional measurements were performed on samples irradiated at 80 K with 1.8-MeV Kr and 295 K with 1.7-MeV Kr. It was observed that the mixing is the same at 6 K as at 80 K but that it is somewhat greater at 295 K. It was also found that at both 80 and 295 K the mixing is the same for 500-keV as for 1.7 MeV projectile energies if the irradiations are compared on the basis of deposited damage energy. Another set of mixing measurements were performed on Ni and Ti markers in Hf and Hf markers in Ni at 6, 80, and 295 K. Although Ni is known to be a fast thermal diffusing atom in Hf, only a 50% difference in ion beam mixing was observed for the Ni and Ti markers at 6 or 80 K. For these marker systems, the mixing was also approximately the same at 6 and 80 K. At 295 K, the mixing remained constant for the Ti marker, increased slightly for the Hf marker in Ni, but decreased strongly for the Ni marker in Hf. The results for both sets of measurements are interpreted according to a qualitative picture of the development of displacement cascades obtained from molecular dynamics computer simulations