High-temperature resistance anomaly at a strontium titanate grain boundary and its correlation with the grain-boundary faceting-defaceting transition

A correlation between a grain-boundary structural transition and a change in electrical properties is demonstrated, using a SrTiO3 bicrystalline grain boundary as a model system. A grain-boundary faceting-defaceting transition is seen between 1500 and 1600 degrees C (the grain-boundary of the bicrystal annealed at 1600 degrees C for one day is shown in the figure) accompanied by an abrupt change in grain-boundary electrical impedance.