The effect of oxygen adsorption on Cu-Ni alloys during irradiation studied by SIMS, SIPS and ISS

A series of Cu-Ni alloys have been sputtered by Ar+ and also He+ ion beams. SIMS, SIPS and ISS measurements were made from these alloys under ultra high vacuum, as well as in different oxygen ambients, to study the effect of oxygen, on these techniques and to obtain information on the adsorption process. During oxygen absorption, the secondary ion and photon yields for both elements are enhanced to an extent which depends upon the Ni concentration of the alloy. The results suggest that the nickel concentration modifies the surface oxygen coverage as the oxygen primarily adsorbs to the Ni atoms. This modification of oxygen bonding to the surface would be expected to strongly influence depth profiles of metal-metal interfaces measured by SIMS and SIPS. (orig.)