An Auger microscopy study of the meeting and interdiffusion of pure Pb and Bi adsorbed layers on polycrystalline Cu

The spreading of Pb and Bi adsorbed layers from pure bulk sources, and their intermixing, on a Cu substrate, has been studied by scanning Auger microscopy at 473 K. The pure Pb layer spreads faster than the Bi layer. When the pure layers meet, two phenomena are observed. The junction line of the two adsorbed layers drifts due to a replacement of adsorbed Pb by Bi. Superimposed on this drift, the Pb and Bi layers undergo interdiffusion. The interdiffusion coefficient has been analyzed by the Boltzmann-Matano method.