Probing Charge Accumulation at SrMnO/SrTiO Heterointerfaces via Advanced Electron Microscopy and Spectroscopy.

The last three decades have seen a growing trend toward studying the interfacial phenomena in complex oxide heterostructures. Of particular concern is the charge distribution at interfaces, which is a crucial factor in controlling the interface transport behavior. However, the study of the charge distribution is very challenging due to its small length scale and the intricate structure and chemistry at interfaces.

Direct Observation of Huge Flexoelectric Polarization around Crack Tips.

Flexoelectricity is especially relevant for nanoscale structures, and it is expected to be largest at the tip of cracks. We demonstrate the presence of a huge flexoelectric polarization at crack tips in SrTiO by direct observation with scanning transmission electron microscopy. We observe an averaged polarization of 62 ± 16 μC cm in the three unit cells adjacent to the crack tip, which is one of the largest flexoelectric polarizations ever reported.