Electronic and magnetic ground states of the Kitaev material candidates $A_2$CeIrO$_6$ ($A$~$=$~Ba,Sr)

ORAL

Abstract

Quantum magnets with significant bond-directional Ising interactions, so-called Kitaev materials, have attracted tremendous attention recently in the search for exotic spin liquid states. Here we present a comprehensive set of measurements that enables us to elucidate the crystal structures, Ir$^{4+}$ single ion properties, and magnetic ground states of the double perovskite iridates $A_2$CeIrO$_6$ ($A$~$=$~Ba,Sr). The crystal structures of Ba$_2$CeIrO$_6$ and Sr$_2$CeIrO$_6$ are found to be cubic and monoclinic respectively, with a large nearest neighbor distance $>$~5~\AA~between Ir$^{4+}$ ions. X-ray absorption spectroscopy and resonant inelastic x-ray scattering were used to establish $J_{eff}$~$=$~1/2 spin-orbit-assisted Mott insulating states, while bulk characterization and neutron powder diffraction identify A-type antiferromagnetic order. These electronic and magnetic ground states are both consistent with expectations for face-centered-cubic magnets with dominant Kitaev exchange, which indicates that spacing magnetic ions far apart may be a promising design principle for uncovering new Kitaev materials.

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Presenters

  • Adam Aczel

    • Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory
    • Oak Ridge Nat. Lab.

Authors

  • Adam Aczel

    • Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory
    • Oak Ridge Nat. Lab.

  • James P.I. Clancy

    • McMaster University

  • Qiang Chen

    • University of Tennessee

  • Haidong Zhou

    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee
    • University of Tennessee, Knoxville
    • Physics, University of Tennessee, Knoxville, TN, United States
    • Physics, University of Tennessee
    • Department of Physics and Astronomy, The University of Tennessee, Knoxville
    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • Department of Physics, University of Tennessee

  • Dalmau Reig-i-Plessis

    • University of Illinois at Urbana-Champaign

  • Greg MacDougall

    • University of Illinois at Urbana-Champaign

  • Jacob Ruff

    • Cornell University
    • CHESS
    • CHESS, Cornell University

  • Mary Upton

    • Argonne Nat. Lab.
    • Argonne National Laboratory

  • Travis J Williams

    • Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Stuart Calder

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak-Ridge National Laboratory

  • Jiaqiang Yan

    • Oak Ridge National Laboratory (USA)
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Materials Science and Technology, Materials Science and Technology
    • Oak Ridge National Lab
    • Materials Science and Engineering, The University of Tennessee