Crystal-Field Effects and the Migration of Transition-Metal Ions in AgCl

The diffusion of a set of consecutive divalent transition-metal ions has been measured in AgCl. Their high-temperature activation energies are found to span the range from 1 to 2 eV and to exhibit a systematic dependence on the number of electrons in the $d$ shell. The relative migration energies can be quantitatively accounted for in terms of the electronic contributions to the energies of the ions, in the normal and activated positions, resulting from crystal-field splittings.