Metal-Insulator-like transition in the LaAlO3/BaTiO3 interface

We report on the electronic properties of LaAlO3/BaTiO3 oxide interfaces. We used pulsed laser deposition to fabricate high quality oxide interfaces between LaAlO3 and BaTiO3 by varying the oxygen partial pressure from 10-6 to 10-4 Torr during the deposition. As the oxygen partial pressure increased, the interface changed from a metal to an insulator. Furthermore, the LaAlO3/BaTiO3 interface fabricated at low oxygen partial pressure showed a temperature-dependent metal-insulator-like transition above room temperature. The metal-insulator-like transition at LaAlO3/BaTiO3 interface seems to be originating from the enhanced electronic carrier concentration due to the ferroelectric transition of BaTiO3 thin film in cooperation with the oxygen vacancy in BaTiO3 layer.