The Hebb-Wagner polarization technique was applied to Fe-doped SrTiO3 single and bicrystals. The polarization was complicated by additional internal redox reactions, and had to be suitably generalized for a bicrystals. It was demonstrated that the electronic and ionic partial conductivities of a grain boundary could be separated by using this technique. The partial conductivities and the charge carrier concentrations thus obtained clearly demonstrated that the electronic and the ionic charge carriers were depleted in the space charge region. That is, that the depletion of ionic ones was more pronounced and in agreement with the double charge on O vacancies.

Determination of Electronic and Ionic Partial Conductivities of a Grain Boundary - Method and Application to Acceptor-Doped SrTiO3. X.Guo, J.Fleig, J.Maier: Solid State Ionics, 2002, 154-155, 563-9