High-Temperature Resistance Anomaly at a Strontium Titanate Grain Boundary and Its Correlation with the Grain-Boundary Faceting-Defaceting Transition

摘要

With the development of nanotechnology, more attention and care should be paid to grain-boundary structure and its structural transition in order to understand the behavior of polycrystalline materials with grain sizes down to nanometer levels. Here, we report direct evidence suggesting a correlation between a grain-boundary structural transition and a change in the electrical property, using a strontium titanate (SrTiO_3) bicrystalline grain boundary as a model system. The electrical properties of grain boundaries in SrTiO_3 play a critical role in barrier-layer devices, such as capacitors and varis-tors.Alt is believed that the electrical behavior depends on the double Schottky barrier established by the interface charge and the associated space charge across the grain boundary.