A study was made of the diffusion of Na+ along the grain boundaries of bicrystals, by using autoradiographic analysis, micro-hardness measurements and micro X-ray spectral analysis. It was deduced that the bulk diffusivity at 450C could be described by an activation energy of 0.65eV.

Cation Diffusion along Boundaries in Alkali Halide Bicrystals. J.E.Geguzin: Fizika Tverdogo Tela, 1966, 8[11], 3248-53