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.

*Work supported by NSERC, CFI-OIT and the Canadian Institute for Advanced Research. The electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a National Facility supported by McMaster University and NSERC.

–

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