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.

–

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