Structural, ferroelectric, electronic and transport properties of BaTiO3/Pt heterostructures grown on MgO(001)

In this work, we describe the structural and ferroelectric properties of BaTiO3(001)/Pt(001) heterostructures grown by pulsed laser deposition on MgO(001) substrates. By combining HAXPES results on the electronic band line-up at the interfaces of Cr/BaTiO3(001)/Pt(001) trilayers with REELS data of the band gap in ultrathin BaTiO3 layers we reconstruct the shape of the potential energy barrier profile across the corresponding ferroelectric tunnel junction (FTJ). I-V characteristics of FTJs with sub-mu m Au/Cr top electrodes reveal a tunneling electroresistance change by the factor of similar to 30 following the ferroelectric polarization reversal. I-V curves are fitted with the experimentally determined electrostatic potential energy profile for the particular polarization direction to derive the quantitative changes in the barrier profile upon polarization reversal. (C) 2013 Elsevier B.V. All rights reserved.