Ohmic Ag/Cu3Ba2YO7-δ micro-contacts on adjacent grains of polycrystalline Fe-doped SrTiO3-samples were used to investigate the local properties of grain boundaries by means of impedance spectroscopy. Experiments on 30 different single grain boundaries permitted conclusions to be drawn concerning the distribution of grain boundary properties. Conventional impedance measurements were also performed on polycrystals, and a brick layer model was used to derive effective properties. A reasonable agreement between the effective parameters, and the average locally obtained parameters, demonstrated that a brick layer analysis of conventional impedance experiments here yielded satisfactory estimates of the grain boundary properties.

The Distribution of Grain Boundary Resistivities in SrTiO3 Polycrystals - a Comparison between Spatially Resolved and Macroscopic Measurements. S.Rodewald, J.Fleig, J.Maier: Journal of the European Ceramics Society, 2001, 21[10-11], 1749-52