Determination of Interlayer Diffusion Parameters for Ag/Ag(111)

Abstract

It is well known that the Ag/Ag(111) epitaxial system grows three dimensionally because of the existence of a relatively high excess diffusion barrier, $\ensuremath{\Delta}{E}_{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.13\phantom{\rule{0ex}{0ex}}\mathrm{eV}$, at the step edges. Several experimental methods have been developed to measure the step edge barrier in this system over a wide coverage range. The probability for an atom to move from a higher to a lower layer depends on both the barrier and the prefactor, so it is important to test whether the prefactors for hopping over a step, ${\ensuremath{\nu}}_{s}$, and for hopping on a terrace, ${\ensuremath{\nu}}_{t}$, are different. We present the results from several experiments on Ag/Ag(111) to conclude that ${\ensuremath{\nu}}_{s}/{\ensuremath{\nu}}_{t}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}10}^{2.0\ifmmode\pm\else\textpm\fi{}0.3}$.