Electric-Field-Induced Ferromagnetism <i>via</i> Cluster Percolation in Ion-Gel-Gated La<sub>1-x</sub>Sr<sub>x</sub>CoO<sub>3-δ</sub> Films

ORAL

Abstract

Electrolyte gating techniques have proven remarkably effective in the study of charge density effects in a variety of conductors. The ability to controllably induce surface charge densities > 1014 cm-2 has led to their extensive use in the study of superconductivity, insulator-metal transitions, and magnetism. In this work we apply electrolyte gating to epitaxial films of La1-xSrxCoO3-δ (LSCO), seeking gate-control of ferromagnetism. Our previous work provided direct evidence of oxygen vacancy creation at positive bias, vs. electrostatic hole accumulation at negative bias, using transport as well as in operando X-ray synchrotron and polarized neutron reflectometry (PNR) measurements [1]. Here, we present detailed gate-control over resistivity, magnetoresistance, magnetization, and Curie temperature under hole accumulation, including gate-induced ferromagnetism verified by PNR. These are discussed in terms of recently developed theory for electrolyte-gate-induced percolation [2].
[1] Walter et al., ACS Nano 10, 7799 (2016). Walter et al., Phys. Rev. Mater., under review (2017).
[2] Orth et al., Phys. Rev. Lett. 118, 106801 (2017)

*Work supported by NSF MRSEC under DMR-1420013, and DOE under DE-SC-0016371 and DE-AC05-00OR22725.

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Presenters

  • Jeffery Walter

    • University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesota

Authors

  • Jeffery Walter

    • University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesota

  • Biqiong Yu

    • School of Physics and Astronomy, University of Minnesota

  • Guichuan Yu

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy, University of Minnesota Twin Cities
    • University of Minnesota

  • Alexander Grutter

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • NIST Center for Neutron Research, NIST -Natl Inst of Stds & Tech
    • NIST -Natl Inst of Stds & Tech

  • Brian Kirby

    • NIST Center for Neutron Research
    • NIST Center for Neutron Research, National Institute of Standards and Technology

  • Julie Borchers

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards & Technology
    • NIST Center for Neutron Research, NIST -Natl Inst of Stds & Tech
    • NIST -Natl Inst of Stds & Tech
    • NIST Center for Neutron Research
    • NIST Center for Neutron Research, NIST

  • Zhan Zhang

    • Advanced Photon Source, Argonne National Laboratory
    • X-ray Science Division, Argonne National Lab

  • Hua Zhou

    • Advanced Photon Source, Argonne National Laboratory

  • Timothy Charlton

    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Lab

  • Haile Ambaye

    • Neutron Scattering Division, Oak Ridge National Laboratory

  • Michael Fitzsimmons

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Peter Orth

    • Department of Physics and Astronomy, Iowa State University
    • Iowa state university/Ames Laboratory
    • Department of Physics and Astronomy & Ames Laboratory, Iowa State University

  • Rafael Fernandes

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy , University of Minnesota
    • School of Physics and Astronomy, Univ of Minnesota - Twin Cities
    • Univ of Minn - Minneapolis
    • School of Phys., Univ. of Minnesota - Minneapolis
    • University of Minnesota

  • Boris Shklovskii

    • Fine Theoretical Physics Institute, University of Minnesota

  • Turan Birol

    • Chemical Engineering and Materials Science, University of Minnesota
    • Chemical Engineering and Material Science, University of Minnesota
    • CEMS, University of Minnesota
    • Department of chemical engineering and materials science,University of Minnesota
    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • Univ of Minnesota - Twin Cities
    • Chemical Engineering and Materials Science, university of minnesota

  • Martin Greven

    • School of Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy, University of Minnesota Twin Cities
    • University of Minnesota

  • Chris Leighton

    • University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesota
    • Chemical Engineering and Materials Science, Univ of Minnesota - Twin Cities