Bond Disproportionation in the Silver Bismuthate Ag<sub>2</sub>BiO<sub>3</sub>

ORAL

Abstract

The stoichiometric silver bismuthate Ag2BiO3 is expected to contain bismuth in the nominal Bi+4 state, but the bismuth ions disproportionate into two distinct sites that render Ag2BiO3 insulating [1]. Recent theoretical predictions of metal-insulator transition and Weyl semimetal state in Ag2BiO3 have revived the interest in this material [2]. However, such novel properties are only expected in the absence of disproportionation of bismuth, where Ag2BiO3 is in the Pnna phase. Here, we examine nature of disproportionation in Ag2BiO3 via X-ray absorption and photoemission spectroscopies. We present an updated band structure for Ag2BiO3 in the Pnn2 (disproportionated) phase, where we have a band gap of 1 eV in agreement with our optical spectroscopy measurement. Furthermore, we present Raman spectroscopy results and highlight the extent of similarities to other disproportionated bismuthates despite the distinct crystal structure Ag2BiO3.

[1] C. B. M. Oberndorfer et al., Solid State Sciences 8, 267 (2006).
[2] J. He et al., Nature Communications 9, 492 (2018).

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Presenters

  • Mohamed Oudah

    • Stewart Blusson Quantum Matter Institute, University of British Columbia
    • University of British Columbia

Authors

  • Mohamed Oudah

    • Stewart Blusson Quantum Matter Institute, University of British Columbia
    • University of British Columbia

  • Minu Kim

    • Max Planck Institute for Solid State Research

  • Ksenia Rabinovich

    • Max Planck Institute for Solid State Research

  • Graham McNally

    • Max Planck Institute for Solid State Research

  • Berkay Kilic

    • Max Planck Institute for Solid State Research

  • Kathrin Küster

    • Max Planck Institute for Solid State Research

  • Robert Green

    • University of British Columbia
    • University of Saskatchewan

  • Kateryna Foyevtsova

    • University of British Columbia

  • Alexander Boris

    • Max Planck Institute for Solid State Research

  • George Albert Sawatzky

    • University of British Columbia

  • Andreas P Schnyder

    • Max-Planck Institute for Solid State Physics
    • Max Planck Institute for Solid State Research
    • MPI Stuttgart

  • Douglas Andrew Bonn

    • University of British Columbia
    • Department of Physics & Astronomy, University of British Columbia
    • Stewart Blusson Quantum Matter Institute, University of British Columbia

  • Bernhard Keimer

    • Solid State Spectroscopy, Max Planck Institute for Solid State Research
    • Max Planck Institute for Solid State Research
    • Solid State Spectrsocopy, Max Planck Institute for Solid State Research
    • Max Plank Institute for Solid State Research

  • Hidenori Takagi

    • Max Planck Institute for Solid State Research
    • University of Tokyo