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

Abstract

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) Tort 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. (C) 2010 Elsevier B.V. All rights reserved.