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)

*Department of Energy, National Science Foundation, National Basic Research Program of China, Irvine Materials Research Institute

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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