Ferroelectric Size-effect on BiFeO$_{3}$ Films in Ultra-high Vacuum

ORAL

Abstract

The ferroelectric size effect is a highly pursued and controversial topic encompassing the scaling of polar distortion, domain structure and switchable polarization. We have studied epitaxial BiFeO$_{3}$ films using ultrahigh vacuum piezoresponse force microscopy. The films in vacuum develop out-of-plane polarization domains which, based on their lateral dimensions, drastically violate the Kittel law. From the analysis of the piezoresponse amplitude, we have established that the presence of a topographic island induces in-plane rotation of the polarization vector by 90$^{o}$. These findings are analyzed using a first-principles based model Hamiltonian approach. We have also obtained stable and reproducible piezoresponse hysteresis loops on the 2 nm films. Experiments conducted at the Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, sponsored by the Division of Scientific User Facilities, U.S. Department of Energy.

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Authors

  • Peter Maksymovych

    • Oak Ridge National Laboratory, TN, 37831

  • Stephen Jesse

    • Oak Ridge National Laboratory, TN, 37831

  • Sergey Lisenkov

    • University of Arkansas, AK, 72701

  • Laurent Bellaiche

    • 21-st century Professor in Nanotechnology
    • University of Arkansas, AK, 72701

  • Nina Balke

    • University of California, Berkeley, CA, 94720

  • Mark Huijben

    • University of California, Berkeley, CA, 94720

  • R. Ramesh

    • University of California at Berkeley
    • University of California, Berkeley, CA, 94720
    • University of California-Berkeley
    • Department of Physics, and Material Science and Engineering, University of California, Berkeley, CA 94720, USA.
    • Department of Physics, UC Berkeley
    • Dept. of Materials Science and Engineering, University of California, Berkeley, CA 94720

  • Arthur P. Baddorf

    • Oak Ridge National Laboratory, TN, 37831

  • Sergei V. Kalinin

    • Oak Ridge National Laboratory, TN 37831
    • Oak Ridge National Laboratory, TN, 37831