A serial sectioning technique was used to study the diffusion of 203Hg into pure or OH-doped crystals. The diffusion data for pure material (table 66) indicated that the free energy of association for the Hg-ion plus cation-vacancy complex varied from 0.75 to 0.80eV; an abnormally large value. The diffusivity, for temperatures ranging from 559 to 449C, could be described by:

D (cm2/s) = 8.18 x 10-5 exp[-0.57(eV)/kT]

The presence of OH was shown to cause extreme distortions of the concentration versus distance curves by forming maxima in the Hg concentration well away from the surface of the crystal. The maxima were thought to arise from the formation of Hg-ion plus OH-ion compounds.

The Diffusion of Mercury in Purified KCl and the Effect of OH- on Diffusion. C.A.Allen, W.J.Fredericks: Physica Status Solidi B, 1973, 55[2], 615-22