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Atomic tunneling in crystalline BaTiS<sub>3</sub>

ORAL

Abstract

BaTiS3 exhibits a hexagonal perovskite structure comprised of columns of sulphur coordinated Ti linked by barium making it a quasi-1D structure. Neutron pair distribution function measurements reveal that the Ti atomic displacement parameters increase with decreasing temperature. This observation suggest proximity to a ferroelectric type phase transition or ground-state dynamic disorder. By combining inelastic x-ray scattering phonon spectroscopy and high-resolution inelastic neutron scattering we find evidence for the dynamic disorder scenario for Ti occupying a double-well potential. These dynamics persist into the quantum regime and atomic tunneling with 0.4 meV tunneling splitting is observed. This unique tunneling dynamics has profound consequences on the thermal conductivity and suggest a novel mechanism for thermal transport design.

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Presenters

  • Raphael Hermann

    Oak Ridge National Lab, Oak Ridge National Laboratory

Authors

  • Raphael Hermann

    Oak Ridge National Lab, Oak Ridge National Laboratory

  • Michael E Manley

    Oak Ridge National Laboratory

  • Barry Winn

    Oak Ridge National Lab, Oak Ridge National Laboratory

  • Katharine Page

    Oak Ridge National Laboratory

  • Austin Minnich

    Caltech, Applied Physics and Mechanical Engineering, California Institute of Technology, California Institute of Technology

  • Jaeyun Moon

    California Institute of Technology

  • Ahmet Alatas

    Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory, APS, Argonne National Laboratory

  • Jayakanth Ravichandran

    University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, University of Southern California, Los Angeles