Phase transformation and hole doping in iridate thin films by controlled oxygen annealing

ORAL

Abstract

In an effort to metallize Ir-based perovskites through hole doping, we anneal epitaxially-grown thin films of Sr2IrO4 at controlled oxygen pressures. The post-annealed films show a drop in room-temperature resistivity of up to 3 orders of magnitude, and an evolution from insulating to semimetallic behavior. Scanning transmission electron microscopy, x-ray diffraction, and x-ray absorption spectroscopy reveal a structural transformation to a novel pseudocubic phase, increasing with annealing time, pressure, and reduced film thickness. The evolution towards metallicity is attributed to the phase transformation, interstitial oxygens, and Ir vacancies. We discuss the prospects of achieving hole-doped superconductivity in this spin-orbit semimetal.

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Presenters

  • Hao Zhang

    Department of Physics, University of Toronto, University of Toronto

Authors

  • Hao Zhang

    Department of Physics, University of Toronto, University of Toronto

  • Patrick Clancy

    Trent University, Department of Physics, University of Toronto, University of Toronto

  • Ambrose Seo

    Department of Physics and Astronomy, University of Kentucky

  • Christopher McMahon

    Department of Physics and Astronomy, University of Waterloo

  • David Hawthorn

    Department of Physics and Astronomy, University of Waterloo

  • Gianluigi Botton

    Department of Materials Science and Engineering, McMaster University

  • Young-June Kim

    Physics, University of Toronto, Department of Physics, University of Toronto, University of Toronto

  • John Wei

    Department of Physics, University of Toronto, Univ of Toronto