Influence of nuclear energy deposition density on the ion-beam mixing of metallic bilayers

Abstract

The influence of nuclear energy deposition density (ε) on the ion-beam mixing process is studied in the case of NiZr and FeZr bilayers. Nickel and iron crystals covered with a thin zirconium layer were irradiated at liquid nitrogen temperature with ions of various masses (from N to Xe), which provide values of ε in the range 25–440 eV/Å. The mixing parameters were determined via in situ RBS during irradiation. The variance of the distribution function of mixed atoms ( σ 2) is found to increase linearly with the ion fluence for all the ions used in the experiment. The mixing rate exhibits a linear variation with ε, above a threshold of ∼ 25 eV/Å, for the two systems studied.