STOICHIOMETRY EFFECTS AT CU-NI ALLOY SURFACES DURING 5 KEV AR ION SPUTTERING AT ROOM TEMPERATURES

The surface and subsurface compositional changes of Cu-Ni alloys with different stoichiometries were studied in situ using 5 ke V Ar ion spu ttering and X-ray photoelectron spectroscopy. The altered layer formed at room temperature exhibits enrichment of Cu-atoms at the surface du e to segregation phenomena and diffusion. The size of the effect depen ds on the initial composition of the alloy. Additional information on the elemental depth distribution was obtained by varying the photoelec tron take-off angle. Modeling of the preferential sputtering of Cu ato ms and of the depth distributions was also carried out. The simulation s allowed to distinguish between the temperature and ballistic effects during the ion beam bombardment.