Lattice dynamics calculations of the jump frequencies for various cation and anion isotopes were carried out by assuming that vacancies played an active role. The isotope effect was also deduced. The results indicated that the diffusion was governed mainly by a single vacancy mechanism.

Y.Madhavan, K.Ramachandran, T.M.Haridasan: Physica Status Solidi B, 1989, 154[1], 55-60