Optically Induced Picosecond Timescale Oxygen Octahedral Rotations in Multiferroic BiFeO<sub>3</sub> Thin Films

ORAL

Abstract

Structural effects originating from above bandgap optical excitation provide a route for ultrafast control of ferroelectricity and magnetism in multiferroic materials. The electrical and magnetic properties of multiferroic BiFeO3 depend on structural distortions arising from the rotations and tilts of FeO6 octahedra. We report an x-ray free-electron laser diffraction study designed to probe the dynamics of oxygen octahedral rotation (OOR) in a 35 nm BiFeO3 film epitaxially deposited on a (001) SrTiO3 substrate following a 3.1 eV optical pump pulse. The diffraction measurement recorded the time dependence of the reciprocal space location and intensities of half-integer reflections (0.5 0.5 2.5) and (0.5 1.5 2.5). Both reflections shifted to a lower out-of-plane wavevector following the optical excitation indicating that there is a transient photoinduced lattice expansion. The intensity of the (0.5 0.5 2.5) reflection depends on the in-plane OOR angles, providing a straightforward way to determine the tilt angle. The intensities of (0.5 1.5 2.5) reflections depend on both in-plane and out-of-plane OOR angles. A model for the dependence of the intensity on the in-plane and out-of-plane OOR angles was used to interpret the diffraction results.

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Publication: H. J. Lee, N. Li, D. Sri Gyan, Y. Ahn, E. C. Landahl, J. Carnis, J. Y. Lee, T. Y. Kim, S. Unithrattil, J. Y. Jo, S. H. Chun, S. Kim, S. Y. Park, I. Eom, C. Adamo, D. G. Schlom, H. Wen, S. Labat, and P. G. Evans, "Optically Induced Picosecond Timescale Oxygen Octahedral Rotations in Multiferroic BiFeO3 Thin Films". (In Preparation, 2021)

Presenters

  • Ni Li

    • University of Wisconsin-Madison

Authors

  • Deepankar Sri Gyan

    • University of Wisconsin-Madison

  • Ni Li

    • University of Wisconsin-Madison

  • Hyeonjun Lee

    • University of Wisconsin-Madison

  • Youngjun Ahn

    • University of Michigan

  • Eric C Landahl

    • DePaul University

  • Jerome Carnis

    • Aix Marseille Université, Université de Toulon, CNRS, IM2NP, Marseille, France; and, ESRF - The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
    • Aix Marseille Université, Université de Toulon, CNRS, IM2NP, Marseille, France; ESRF - The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France

  • Jun Young Lee

    • Gwangju Institute of Science and Technology, Gwangju 61005, South Korea

  • Tae Yeon Kim

    • Gwangju Institute of Science and Technology, Gwangju 61005, South Korea

  • Sanjith Unithrattil

    • Gwangju Institute of Science and Technology, Gwangju 61005, South Korea

  • Ji Young Jo

    • Gwangju Institute of Science and Technology, Gwangju 61005, South Korea

  • Sae Hwan Chun

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea

  • Sunam Kim

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea

  • Sang-Youn Park

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea
    • Pohang Accelerator Laboratory (PAL)

  • Intae Eom

    • Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, South Korea

  • Carolina Adamo

    • Stanford Univ

  • Darrell G Schlom

    • Cornell University

  • Haidan Wen

    • Argonne National Laboratory

  • Stephane Labat

    • Aix Marseille Université, Université de Toulon, CNRS, IM2NP, Marseille, France

  • Paul G Evans

    • University of Wisconsin - Madison