A model of the kinetics and equilibria of surface segregation in the monolayer regime

A kinetic model of surface segregation based on foreign atom movement in an appropriate potential is developed. It is used to calculate the time and temperature dependence of surface concentration and the concentration distribution perpendicular to the surface for the case of structure limited surface enrichment. The results give an explanation for Auger electron spectroscopy obervations of the segregation of tin at the surface of copper single crystals. In-depth profiles of composition obtained by sputtering are in agreement with predictions from the model. Deviations from other models of segregation kinetics are briefly discussed.