The effects of foreign impurity ions which were located on the conduction planes of the ”-alumina lattice were analyzed by using molecular dynamics techniques. The impurity ions were assumed to be K and Ca, and Na in the conduction plane was replaced by these ions. It was found that the lattice expanded perpendicularly to the conduction plane when K ions were introduced, and that Ca ions did not contribute to the expansion of the lattice. Finally, both K and Ca ions reduced the mean square displacement of the Na ions. This was attributed to a decreased Na ion diffusivity.

O.Ito, M.Mukaide, M.Yoshikawa: Solid State Ionics, 1995, 80[3-4], 181-7