Structural, ferroelectric, electronic and transport properties of BaTiO sub(3)/Pt heterostructures grown on MgO(OO1)

In this work, we describe the structural and ferroelectric properties of BaTiO sub(3)(001)/Pt(001) heterostructures grown by pulsed laser deposition on MgO(OOl) substrates. By combining HAXPES results on the electronic band line-up at the interfaces of Cr/BaTiO sub(3)(001)/Pt(OO1) trilayers with REELS data of the band gap in ultrathin BaTiO sub(3) 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.