On the charge transfer energy in iridates: a hard x-ray photoelectron spectroscopy study

ORAL

Abstract

We have investigated the electronic structure of iridates in the double perovskite crystal structure containing either Ir4+ or Ir5+ using hard x-ray photoelectron spectroscopy (HAXPES). The experimental valence band spectra can be well reproduced using tight binding calculations including only the Ir 5d, O 2p and O 2s orbitals with parameters based on the down-folding of the density-functional band structure results. We found that regardless the A and B cations, the A2BIrO6 iridates have essentially zero O 2p to Ir 5d charge transfer energies. They are extremely covalent systems with the consequence is that the magnetic exchange interactions become very long-ranged, thereby hampering the materialization of the Kitaev model. Nevertheless, it still would be possible to realize a spin-liquid system using the iridates with a proper tuning of the various competing exchange interactions .

*We acknowledge supported by the Deutsche Forschungsgemeinschaft through SFB 1143 (project-id 247310070) and Grant No. 320571839.

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Presenters

  • Daisuke Takegami

    • Max Planck Institute for Chemical Physics of Solids

Authors

  • Daisuke Takegami

    • Max Planck Institute for Chemical Physics of Solids

  • Deepa Kasinathan

    • Max Planck Institute for Chemical Physics of Solids

  • Klaus Wolff

    • Max Planck Institute for Chemical Physics of Solids

  • Simone G Altendorf

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Chun-Fu Chang

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Katharina Hoefer

    • Max Planck Institute for Chemical Physics of Solids

  • Anna Meléndez-Sans

    • Max Planck Institute for Chemical Physics of Solids

  • Yuki Utsumi

    • Max Planck Institute for Chemical Physics of Solids

  • Federico Meneghin

    • Politecnico di Milano

  • Thai Duy Ha

    • Department of Electrophysics, National Chiao Tung University

  • Chien-Han Yen

    • Department of Physics, National Tsing Hua University

  • Kai Chen

    • Institute of Physics II, University of Cologne

  • Chang-Yang Kuo

    • National Synchrotron Radiation Research Center
    • National Synchrotron Radiation Research Center, Hsinchu, Taiwan

  • Y. F. Liao

    • National Synchrotron Radiation Research Center
    • National Synchrotron Radiation Research Center, Hsinchu, Taiwan

  • Ku-Ding Tsuei

    • National Synchrotron Radiation Research Center
    • National Synchrotron Radiation Research Center, Hsinchu, Taiwan

  • Ryan Morrow

    • Leibniz Institute for Solid State and Materials Research IFW Dresden

  • Sabine Wurmehl

    • Leibniz Institute for Solid State and Materials Research IFW Dresden

  • B.E. Prasad

    • Max Planck Institute for Chemical Physics of Solids

  • Martin Jansen

    • Max Planck Institute for Solid State Research

  • Alexander Komarek

    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Philipp Hansmann

    • Max Planck Institute for Chemical Physics of Solids

  • Liu Hao Tjeng

    • Max Planck Institute for Chemical Physics of Solids