Synthesis and Electronic Characterization of Nd<sub>2-x</sub>Sr<sub>x</sub>NiO<sub>4</sub> thin films (0 ≤ x ≤ 1.4)

ORAL

Abstract

Layered nickelates have been studied extensively over the last three decades due to their structural similarities to the high-Tc superconducting cuprates. Using reactive oxide molecular beam epitaxy (MBE), we synthesize Nd2-xSrxNiO4 thin films for x = 0-1.4 to probe the properties and electronic structure as a function of hole doping. The samples with lower doping show semiconducting behavior across the temperatures probed with an onset of metallic conductivity at x = 1.2. We also present polarization-dependent O-K and Ni-L2,3 x-ray absorption spectra to track the evolution of the oxygen-nickel hybridization, distribution of holes between O-2p and Ni-3d states and the nickel oxidation state across the series. Angle-resolved photoemission spectroscopy (ARPES) measurements reveal a Fermi surface that comprises a cuprate-like hole-pocket of dx2-y2 character with an additional electron pocket of d3z2-r2 character at Γ, qualitatively consistent with DFT calculations for paramagnetic La2NiO4 In contrast to measurements of the related bulk compound Eu0.9Sr1.1NiO4, we do not observe a momentum-dependent pseudogap and observe an entirely two-dimensional Fermi surface with no kz dispersion.

*Research is primarily supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Award No. DE-SC0021925. This work used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. Device fabrication work was performed at Harvard University's Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), supported by the National Science Foundation under NSF Grant No. 1541959. N.K.T. acknowledges the support of a Ford Fellowship. D.F.S. acknowledges support from the NSF Graduate Research Fellowship Grant No. DGE-1745303. J.A.M acknowledges support from the Packard Foundation and the Sloan Foundation. Y.Z. and I.E. were supported by The Rowland Institute at Harvard.

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Publication: Nicole K. Taylor et al. "Synthesis and Electronic Characterization of Nd$_{2-x}$Sr$_x$NiO$_4$ thin films ($0 \leq x \leq 1.4)$," Manuscript submitted to Physical Review Materials, August 2024

Presenters

  • Nicole K Taylor

    • School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA

Authors

  • Nicole K Taylor

    • School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA

  • Dan Ferenc Segedin

    • Department of Physics, Harvard University, Cambridge, MA, USA

  • Ari B Turkiewicz

    • Department of Physics, Harvard University, Cambridge, MA, USA

  • Yang Zhang

    • The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA

  • Spencer T Doyle

    • Department of Physics, Harvard University, Cambridge, MA, USA

  • Grace A Pan

    • Department of Physics, Harvard University, Cambridge, MA, USA

  • Haoyue Jiang

    • Lawrence Berkeley National Laboratory
    • Department of Physics, University of California at Berkeley, Berkeley, CA, USA

  • Aaron Bostwick

    • ALS, LBNL, Berkeley
    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, LBNL
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Christopher Jozwiak

    • ALS, LBNL, Berkeley
    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, E.O. Lawerence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Eli Rotenberg

    • ALS, LBNL, Berkeley
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Alessandra Lanzara

    • University of California, Berkeley
    • Department of Physics, University of California at Berkeley, Berkeley, CA, USA
    • Department of Physics, University of California, Berkeley

  • Ismail El Baggari

    • Harvard University
    • The Rowland Institute at Harvard
    • The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA

  • Charles M Brooks

    • Harvard University
    • Department of Physics, Harvard University, Cambridge, MA, USA

  • Alpha T N'Diaye

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Luca Moreschini

    • University of California, Berkeley
    • Department of Physics, University of California at Berkeley, Berkeley, CA, USA
    • Department of Physics, University of California, Berkeley

  • Julia A Mundy

    • Harvard University
    • Department of Physics, Harvard University, Cambridge, MA, USA