Cation Ordering in Layered Nickelates

ORAL

Abstract

The single layer Ruddlesden-Popper nickelates present a model system to understand how the effects of digital dopant cation ordering may affect the properties of 2-dimensional conducting sheets. We investigate the effects of aliovalent A-site cation order on LaSrNiO$_{4}$ films. Using molecular beam epitaxy, we interleave full layers of SrO and LaO in a series of chemically equivalent films, varying the pattern of SrO and LaO layers relative to the NiO$_{2}$ layers. Through synchrotron surface x-ray diffraction and Coherant Bragg Rod Analysis (COBRA), we directly investigate the A-site cation order and the resulting atomic displacements for each ordering pattern. We correlate these results with theoretical calculations and transport measurements of the layered nickelate films.

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Authors

  • Brittany Nelson-Cheeseman

    • School of Engineering, University of St. Thomas \& Materials Science Division, Argonne National Laboratory
    • Argonne National Laboratory

  • Hua Zhou

    • Advanced Photon Source, Argonne National Lab

  • Antonio Cammarata

    • Dept of Materials Science and Engineering, Drexel University

  • Jason Hoffman

    • Argonne National Laboratory
    • Materials Science Division, Argonne National Lab

  • Prasana Balachandran

    • Dept of Materials Science and Engineering, Drexel University
    • Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104
    • Drexel University

  • James Rondinelli

    • Drexel University
    • Dept of Materials Science and Engineering, Drexel University
    • Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104
    • Department of Materials Science and Engineering, Drexel University

  • Anand Bhattacharya

    • Argonne National Laboratory
    • Materials Science Division \& Center for Nanoscale Materials, Argonne National Lab
    • Argonne National Lab
    • Materials Science Division and Center for Nanoscale Materials, Argonne National Laboratory