The simultaneous diffusion of Cd and Pb was studied. The experimental conditions were such that the concentration of Pb2+ was about 10 times the concentration of Cd2+. The Cd2+ profile exhibited an inflection point between a region of rapid diffusion and a region of more normal diffusion. This was attributed to a normal common-ion reaction. The diffusion profile for the Pb ion could be fitted by:

D (cm2/s) = 1.00 x 10-3 exp[-0.908(eV)/kT]

J.L.Krause, W.J.Fredericks: Journal de Physique - Colloques, 1973, 9, 25-35