Evidence for crystal-face specificity in surface segregation of CuNi alloys

We present experimental evidence for crystal-face specificity in surface segregation at CuNi alloy surfaces using angular x-ray photoemission spectroscopy, secondary-ion mass spectroscopy, and "chemisorptive titration" techniques. More copper enrichment is found on the (100) surface than the (111) surface of a 17% Cu-83% Ni alloy, in agreement with predictions from current segregation theories. © 1981 The American Physical Society.