Interface Induced Ferroelectric Phase Transformation in SrTiO3.

The transport properties across bicrystal interfaces in SrTiO3 are quantified with 4-pt probe, Hall measurements, scanning impedance microscopy and scanning tunneling microscopy. The properties are related to the structure determined by transmission electron microscopy, energy loss spectroscopy and first principles calculations. An anomaly in the temperature dependence of the transport properties arises from the charge trapped at the interface, which induces dipole ordering adjacent to the boundary. This represents the first observation of interface induced ferroelectricity in SrTiO3.