The kinetics of bulk-to-surface Sn diffusion in a dilute (111) single crystal was investigated, at temperatures ranging from 678 to 794K, by using Auger electron spectroscopic and low-energy electron diffraction techniques. It was shown that a sputter-time correction was essential in order to obtain an accurate estimate of the diffusion coefficient. After deriving the segregation equation for limited surface site accessibility, modified Darken equations were used, together with sputter-time corrections, to deduce the diffusion coefficient and segregation energy from the kinetic data. The diffusion data could be described by:

D (m2/s) = 7 x 10-6exp[-168(kJ/mol)/RT]

E.C.Viljoen, J.Du Plessis, H.C.Swart, G.N.Van Wyk: Surface Science, 1995, 342, 1-10