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.

–

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