Unusual Sn State in the Superconducting Disordered Selenide Ag<sub>1-<i>x</i></sub>Sn<sub>1+<i>x</i></sub>Se<sub>2</sub>

ORAL

Abstract

We investigate the NaCl-type superconducting series Ag1-xSn1+xSe2 by means of XPS and Mössbauer spectroscopy. By varying the Ag/Sn ratio we observe a change in the ratio of 2+ and 4+ state of Sn as probed by XPS, with increasing 2+ state as the Sn amount is increased. In contrast, we detect only one state for Sn in the Mössbauer spectra, which corresponds to the unusual 3+ state for Ag:Sn of 1:1. We study the Mössbauer spectra at low temperature to elucidate the charge fluctuations scenario for Sn. Furthermore, we calculate the band structure of AgSnSe2, which reveal contributions from all three elements near the fermi level. We discuss the experimentally measured state of Sn in light of our calculations.

*We thank the Max Planck-UBC-UTokyo Center for Quantum Materials for support.

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Presenters

  • Mohamed Oudah

    • University of British Columbia
    • Max Planck Institute for Solid State Research, Stuttgart, Germany

Authors

  • Mohamed Oudah

    • University of British Columbia
    • Max Planck Institute for Solid State Research, Stuttgart, Germany

  • Jose Lado

    • Department of Applied Physics, Aalto University
    • Aalto University
    • Applied Physics, Aalto University
    • Institut für Theoretische Physik, ETH Zürich, Zürich, Switzerland

  • Shinji Kitao

    • Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan

  • Graham McNally

    • Max Planck Institute for Solid State Research, Stuttgart, Germany

  • Kathrin Küster

    • Max Planck Institute for Solid State Research, Stuttgart, Germany
    • Max Planck Institute for Solid State Research

  • Makoto Seto

    • Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan

  • Douglas A. Bonn

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

  • Bernhard Keimer

    • Max Planck Inst for Solid State Research
    • Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
    • Max Planck Institute for Solid State Physics
    • Max Planck Institute for Solid State Research
    • Solid State spectroscopy, Max Planck Institute for Solid State Research
    • Max Planck Institute for Solid State Research, Stuttgart, Germany

  • Manfred W Sigrist

    • ETH Zurich
    • Institute for Theoretical Physics, ETH Zurich, Switzerland
    • Institut für Theoretische Physik, ETH Zürich, Zürich, Switzerland

  • George Albert Sawatzky

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

  • Hidenori Takagi

    • University of Tokyo (Japan)
    • Max Planck Institute for Solid State Research
    • Max Planck Institute for Solid State Research, Stuttgart, Germany