Charge Density imaging of a ferroelectric-insulator interface with sub-Å resolution

ORAL

Abstract

In complex oxide heterostructures, charge redistribution determines the characteristics of the material and can have significant influence on the behavior of the material. For example, the 2-dimensional electron gas at an LaAlO3-SrTiO3 interface is linked with superconductivity and ferromagnetism at the interface [1]. Although first principles calculations can provide highly detailed charge density maps that illustrate these phenomena, experimental methods often cannot resolve the same features at interfaces or nanostructures with high spatial resolution. Here we demonstrate the imaging of electron charge at interfaces in heterogeneous perovskite structures at atomic resolution using aberration corrected scanning transmission electron microscopy. The charge density mapping is determined using the 2D diffraction pattern acquired with a high-speed pixelated detector [2]. At a BiFeO3-SrTiO3 interface, we found evidence of charge separation caused by the penetration of the electric field from the polarized BiFeO3 into the insulating SrTiO3.

[1] J. A. Bert, et al., Nature Physics 7, 767 (2011)
[2] K. Müller, et al., Nature Communications 5, 5653 (2014)

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Presenters

  • Christopher Addiego

    Department of Physics and Astronomy, University of California, Irvine

Authors

  • Christopher Addiego

    Department of Physics and Astronomy, University of California, Irvine

  • Wenpei Gao

    Department of Chemical Engineering and Materials Science and Department of Physics and Astronomy, University of California, Irvine, Department of Materials Science and Engineering, University of California, Irvine

  • Hui Wang

    Department of Physics and Astronomy, University of California, Irvine, CA, United States, Department of Physics and Astronomy, University of California, Irvine

  • Xingxu Yan

    Department of Materials Science and Engineering, University of California, Irvine

  • YUSHENG HOU

    University of California, Irvine, Department of Physics and Astronomy, University of California, Irvine

  • Dianxiang Ji

    National Laboratory of Solid State Microstructures, and College of Engineering and Applied Sciences, Nanjing University, Nanjing University, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing Univ

  • Colin Heikes

    NIST, National Institute of Standards and Technology, Department of Materials Science and Engineering, Cornell University

  • Yi Zhang

    Department of Materials Science and Engineering, University of California, Irvine

  • Linze Li

    Department of Materials Science and Engineering, University of California, Irvine

  • Huaixun Huyan

    Department of Chemical Engineering and Materials Science and Department of Physics and Astronomy, University of California, Irvine, Department of Materials Science and Engineering, University of California, Irvine

  • Thomas F Blum

    Department of Physics and Astronomy, University of California, Irvine

  • Toshihiro Aoki

    Irvine Materials Research Institute, University of California, Irvine

  • Yuefeng Nie

    College of Engineering and Applied Sciences, Nanjing University, National Laboratory of Solid State Microstructures, and College of Engineering and Applied Sciences, Nanjing University, Nanjing University, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing Univ

  • Darrell G. Schlom

    Cornell University, Cornell University, Ithaca, New York 14853, USA, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Materials Science & Engineering, Cornell University, Department of Materials Science and Engineering,, Cornell University, Materials Science and Engineering, University of Cornell

  • Ruqian Wu

    University of California, Irvine, Department of Physics and Astronomy, University of California, Irvine, CA, United States, Fudan University, Department of Physics and Astronomy, University of California, Irvine

  • Xiaoqing Pan

    Department of Chemical Engineering and Materials Science and Department of Physics and Astronomy, University of California, Irvine, Department of Materials Science and Engineering, Department of Physics and Astronomy, University of California, Irvine