Use of AES to determine sputter‐induced concentration profiles in Cu–Ni alloys

Abstract

AbstractThe difference in escape depth of Auger electrons of different energies was used to determine sputter‐induced concentration profiles in Cu‐Ni alloys. Alloys with Cu/Ni concentrations of 70/30, 50/50 and 30/70 at.% were bombarded with 2 keV Ar+ ions. After equilibrium has been reached, an AES spectrum for the alloy was recorded using a 12‐bit analogue‐to‐digital converter interfaced with a computer. Spectra for the pure elements, Cu and Ni, were recorded under identical conditions and were used to generate Auger spectra for the alloys that could be compared with the experimental data. The layer concentration values for which the best fit was obtained were used to construct a concentration profile. The results indicate a Cu‐enriched first layer followed by a depleted zone. It is concluded that the bombardment of Cu‐Ni alloys by 2 keV Ar+ ions leads to the segregation of copper and that AES can be used to determine sputter‐induced profiles if the necessary experimental precautions are taken.