Optimizing Synthesis of Superconducting Infinite-Layer Nickelates

ORAL

Abstract

Superconductivity was recently discovered in the infinite-layer nickelate Nd0.8Sr0.2NiO2.1 To proceed with further systematic studies in the superconducting properties of this material, it is important to establish a reproducible method to synthesize single-phase, single-crystalline Nd0.8Sr0.2NiO2. The synthetic route to this infinite-layer nickelate structure poses two major challenges. First, the precursor perovskite phase is difficult to stabilize due to the unusually high formal nickel valence of Ni+3.2 and the structural instability induced by chemical doping. Second, topochemical reduction on perovskite nickelates have shown limitations in coherent transition to the infinite-layer phase.2 After careful optimization, we have successfully established a reproducible method to stabilize Nd0.8Sr0.2NiO2 (001) epitaxial thin films on SrTiO3 (001) substrate by pulsed-laser deposition and CaH2-assisted topochemical reduction. The details of the optimization process and the dependence of structural and superconducting properties on growth conditions will be discussed.

1 Li, D. et al., Nature 572, 624 (2019).
2 Kawai, M. et al., Cryst. Growth Des. 10, 2044 (2010).

**Supported by DOE BES MSD (DE-AC02-76SF00515), the Moore Foundation (GBMF4415), and DOD AFOSR (FA 9550-16-1-0305).

–

Presenters

  • Kyuho Lee

    • Physics, Stanford University
    • Stanford University

Authors

  • Kyuho Lee

    • Physics, Stanford University
    • Stanford University

  • Danfeng Li

    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
    • SLAC National Accelerator Lab.
    • Physics, Stanford University
    • Stanford University
    • Applied Physics, Stanford University

  • Motoki Osada

    • Stanford University
    • Physics, Stanford University
    • Materials Science and Engineering, Stanford University

  • Bai Yang Wang

    • Department of Physics, Stanford University
    • Physics, Stanford University
    • Stanford University

  • Berit Goodge

    • Cornell University
    • Applied and Engineering Physics, Cornell University

  • Lena Fitting Kourkoutis

    • Cornell University
    • Applied and Engineering Physics, Cornell University
    • Kavli Institute at Cornell for Nanoscale Science

  • Harold Hwang

    • Institute for Materials and Energy Sciences, Stanford University
    • Stanford University
    • Department of Applied Physics, Stanford University
    • Applied Physics, Stanford University
    • SIMES, SLAC
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
    • SLAC National Accelerator Lab.
    • Physics, Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory