A gas-solid isotope exchange technique was used to study the diffusion of 36Cl in crystallites which had been prepared by reacting spectrographically pure Ni sponge with distilled HCl. The activation energy for Cl ion migration, at temperatures ranging from 180 to 340C, was found to be 1.01eV.

Y.Sensui: Bulletin of the Chemical Society of Japan, 1972, 45[9], 2677-83