Oxygen induced segregation of aluminum to alpha-Cu-Al(100) alloy surfaces studied by low energy ion scattering and X-ray photoelectron spectroscopy

摘要

The effect of annealing temperature on the surface composition of alpha-Cu-Al(100) alloys for aluminum concentrations of 5, 1.2 and 17 at% was investigated using X-ray photoelectron spectroscopy (XPS) and low energy ion scattering (LEIS). Two initial states of the sample surfaces were examined: sputter-cleaned and oxidized. The effect of annealing temperature on segregation is different for sputter-cleaned and oxidized samples. Aluminum preferential sputtering and strong oxygen induced aluminum segregation were detected oil all examined samples. Whilst for the sputter-cleaned surfaces a small thermal induced segregation was observed, the combination of annealing and oxygen exposure resulted in aluminum enrichment in the 100-300% range relative to the bulk concentration. The segregation rate is proportional to the aluminum concentration for sputter-cleaned surfaces and displays a maximum for the oxidized alpha-Cu-Al(12 at.%)(100) surface. (c) 2006 Published by Elsevier B.V.