The diffusivity of Cd tracers was carefully re-measured. The activation energy for the substitutional diffusion of Cd2+ was 1.17eV. A high degree of association between divalent cations and vacancies at high temperatures was noted, and the activation energy for the jumping of Cd2+ into a cation vacancy was deduced to be 0.88eV. This was about 2.5 times the migration energy of the free unassociated vacancy.

Solute Migration by Interstitials and by Vacancies: Mn2+ and Cd2+ in AgCl. A.P.Batra, L.M.Slifkin: Journal of Physics - C, 1975, 8[18], 2911-22