The sectioning technique was used to study the diffusion of 210Pb into single crystals. The diffusion coefficient increased with increasing Pb concentration, but approached a saturation value at Pb mole fractions of 5 x 10-5 to 10-4 (table 135). On the basis of the saturation values, the activation energy for 210Pb diffusion was estimated to be 0.98eV. Diffusion of Lead Ions in Sodium Chloride. C.A.Allen, D.T.Ireland, W.J.Fredericks: Journal of Chemical Physics, 1967, 46[5], 2000-1