Two methods were presented for obtaining information, concerning the local ionic conductivity, by using point-electrode techniques together with atomic force microscopy. One method made use of the fact that the main resistance decrease occurred within a very small region beneath a point electrode and reflected the local conductivity. By varying the position of the point electrode, inhomogeneous Cd2+ impurity profiles were determined. The diffusion coefficients could then be easily measured. In the second method, the point diameter was varied and thus the thickness and conductivity, as well as the conductivity activation energy of mechanically-induced highly conducting surface layers, could be measured. The method was applied to mechanically pre-treated samples. When using either method, it was found to be necessary to be able to measure impedances which were as high as 500G.

J.Fleig, J.Maier: Solid State Ionics, 1996, 85[1-4], 9-15