An experimental determination of the effect of ion size upon diffusion was performed by measuring the diffusivity of 86Rb in NaCl. In the temperature region near to the melting point, the results obeyed an Arrhenius relationship:

D(cm2/s) = 205 exp[-2.11(eV)/kT]

G.Ara, J.G.Mullen: Physical Review, 1966, 143[2], 663-5