Sputter-enhanced diffusion phenomena in Cu/Ni alloys at elevated temperatures

Compositional changes of the surface and near surface layers were studied in copper-nickel alloys during argon ion bombardment (3 keV) at temperatures up to 873 K, using Auger electron spectroscopy (AES) and x-ray microanalysis (XMA). A long range depletion of copper on the order of 100 nm in thickness was observed depending on the sputtering time, specimen temperature, and ion beam density. An enhanced diffusion of copper was noted in the damaged layer at low temperatures. The apparent activation energy calculated, assuming an Arrhenius type equation, was 5–6 kcal/mol. It is suggested that an interstitial type diffusion mechanism was predominant in the damaged layer.