Synthesis of high-oxidation Y-Ba-Cu-O phases in superoxygenated thin films

ORAL

Abstract

It is known that solid-state reaction in high-pressure oxygen can stabilize high-oxidation phases of Y-Ba-Cu-O superconductors in powder form. We extend this superoxygenation concept of synthesis to thin films which, due to their large surface-to-volume ratio, are more reactive thermodynamically. Epitaxial thin films of YBa2Cu3O7-δ grown by pulsed laser deposition are annealed at up to 700 atm O2 and 900 ○C, in conjunction with Cu enrichment by solid-state diffusion. The films show clear formation of Y2Ba4Cu7O15-δ and Y2Ba4Cu8O16 as well as regions of YBa2Cu5O9-δ and YBa2Cu6O10-δ phases, according to scanning transmission electron microscopy, x-ray diffraction and x-ray absorption spectroscopy. Similarly annealed YBa2Cu3O7-δ powders show no phase conversion. Our results demonstrate a novel route of synthesis towards discovering more complex phases of cuprates and other superconducting oxides [1].
[1] H. Zhang et al., https://arxiv.org/abs/1710.10672

*Work supported by NSERC, CFI-OIT and the Canadian Institute for Advanced Research. The electron microscopy work was carried out at CCEM, a National Facility supported by CFI under the MSI program, McMaster University and NSERC. The XAS work was performed at CLS, which is supported by NSERC, NRC, CIHR, an

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Presenters

  • Chao Zhang

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

Authors

  • Hao Zhang

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

  • Nicolas Gauquelin

    • Department of Materials Science and Engineering, McMaster University
    • Electron Microscopy for Materials Science (EMAT), University of Antwerp

  • Christopher McMahon

    • Department of Physics and Astronomy, University of Waterloo

  • Chao Zhang

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

  • David Hawthorn

    • Department of Physics and Astronomy, University of Waterloo

  • Gianluigi Botton

    • Department of Materials Science and Engineering, McMaster University

  • John Wei

    • Department of Physics, University of Toronto
    • Univ of Toronto