A quantitative analysis of surface segregation and in-depth profile of copper-nickel alloys

By utilizing the difference in escape length of the Auger electrons with different energies, a calculation of the in-depth distribution of atomic concentration at the surface is presented on the basis of Palmberg's physical mechanism. Experimental results on clean surfaces of Cu-Ni alloys over the entire composition region with Auger spectroscopy were performed to make the in-depth profile of surface composition caused by annealing. The alloy composition of the first atomic layer at the surface was plotted against the bulk composition, showing significant enric enrichment of Cu atoms in that layer. The results indicated that the segregation takes place in about four atomic layers at the surface.