Emergence of complex polar order in asymmetric PbTiO$_{\mathrm{3}}$/SrTiO$_{\mathrm{3}}$ superlattices

ORAL

Abstract

Recent work has shown the formation of three-dimensional polar vortices in ferroelectric/paraelectric (PbTiO$_{\mathrm{3}})_{n}$/(SrTiO$_{\mathrm{3}})_{n} $superlattices. This novel phase is stabilized by the interplay of lattice, charge, and orbital degrees of freedom. In this work, we employ a systematic study of the electrical polarization in asymmetric superlattices of PbTiO$_{\mathrm{3}}$ and SrTiO$_{\mathrm{3}}$ grown by pulsed laser deposition. In (PbTiO$_{\mathrm{3}})_{m}$/(SrTiO$_{\mathrm{3}})_{n}$ superlattices, phase-field modeling predicts a systemic evolution of the polarization state in the superlattice as a function of SrTiO$_{\mathrm{3}}$ thickness. We will present results of a combined experimental-theoretical study of the emergence of complex topologies of electrical polarization. To study superlattices as a function of SrTiO$_{\mathrm{3}}$ thickness, we map the electrical polarization using high-resolution scanning transmission electron microscopy in conjunction with piezoresponse force microscopy studies of the ferroelectric domain structures.

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Authors

  • Margaret McCarter

    • Department of Physics, University of California Berkeley, Berkeley, CA, United States
    • University of California Berkeley

  • Ajay Yadav

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Shang-Lin Hsu

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Zijian Hong

    • Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, United States

  • Anoop Rama Damodaran

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Christopher Nelson

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Julia Mundy

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Long-Qing Chen

    • Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, United States

  • Lane Martin

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States

  • Ramamoorthy Ramesh

    • Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, United States