Multiscale electric-field imaging of polarization vortex structures in PbTiO3/SrTiO3 superlattices
Christopher Addiego,
Jacob A. Zorn,
Wenpei Gao,
Sujit Das,
Jiaqi Guo,
Chengqing Qu,
Liming Zhao,
Lane W. Martin,
Ramamoorthy Ramesh,
Long-Qing Chen,
Xiaoqing Pan
Affiliations
Christopher Addiego
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
Jacob A. Zorn
Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
Wenpei Gao
Department of Materials Science and Engineering, University of California, Irvine, California 92697, USA
Sujit Das
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
Jiaqi Guo
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
Chengqing Qu
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
Liming Zhao
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
Lane W. Martin
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
Ramamoorthy Ramesh
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
Long-Qing Chen
Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
Xiaoqing Pan
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
In ferroelectric heterostructures, the interaction between intrinsic polarization and the electric field generates a rich set of localized electrical properties. The local electric field is determined by several connected factors, including the charge distribution of individual unit cells, the interfacial electromechanical boundary conditions, and chemical composition of the interfaces. However, especially in ferroelectric perovskites, a complete description of the local electric field across micro-, nano-, and atomic-length scales is missing. Here, by applying four-dimensional scanning transmission electron microscopy (4D STEM) with multiple probe sizes matching the size of structural features, we directly image the electric field of polarization vortices in (PbTiO3)16/(SrTiO3)16 superlattices and reveal different electric field configurations corresponding to the atomic scale electronic ordering and the nanoscale boundary conditions. The separability of two different fields probed by 4D STEM offers the possibility to reveal how each contributes to the electronic properties of the film.
