Doping- and Strain-Dependent Electrochemical Control of Magnetism in Ion-Gel-Gated Epitaxial La<sub>1-<i>x</i></sub>Sr<i><sub>x</sub></i>CoO<sub>3-δ</sub> Films

ORAL

Abstract

Electrolyte gating has proven remarkably effective in controlling electronic, magnetic, and optical materials properties. Both electrostatic and electrochemical mechanisms occur [1], one example of the latter being the voltage-driven perovskite (P) to brownmillerite (BM) transition found in SrCoO3-d [2], which realizes a ferromagnetic metal/antiferromagnetic insulator transition. In this work, we provide the first complete doping- and strain-dependent study of the ion-gel-gating-induced P to BM transition over the entire La1-xSrxCoO3-δ phase diagram, via transport, magnetometry, and operando synchrotron X-ray diffraction. The electrically-actuated P to BM transition is found to occur over a wide x range, modulating the Curie temperature over ~220 K. Most significantly, the variation in threshold voltage with x and strain point to electrochemical activity controlled by the Co4+/Co3+ ratio, interpreted in terms of trends in thermodynamic rather than kinetic (i.e., oxygen vacancy diffusion) parameters. These results provide global insight into the electrochemical control of this model oxide.
1. Leighton, Nat. Mat. 18, 13 (2018).
2. Lu et al., Nature 546, 124 (2017).
3. Chaturvedi et al., in prep.

*Work supported by NSF MRSEC and DOE Center for Quantum Materials (specifically scattering).

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Presenters

  • VIPUL CHATURVEDI

    • Chemical Engineering and Materials Science, University of Minnesota

Authors

  • VIPUL CHATURVEDI

    • Chemical Engineering and Materials Science, University of Minnesota

  • William M Postiglione

    • Chemical Engineering and Materials Science, University of Minnesota

  • Biqiong Yu

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

  • Wojciech Tabis

    • AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland

  • Sajna Hameed

    • School of Physics and Astronomy, University of Minnesota
    • University of Minnesota
    • School of Physics & Astronomy, University of Minnesota

  • Nikolaos Biniskos

    • School of Physics and Astronomy, University of Minnesota
    • Forschungszentrum Juelich

  • Hua Zhou

    • X-ray Science Division, Advanced Photon Source,, Argonne National Laboratory
    • Advanced Photon Source, Argonne National Laboratory
    • Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
    • Argonne National Laboratory
    • Advanced Photon Source, Argonne National Lab
    • Advanced Photon Source

  • Zhan Zhang

    • Advanced Photon Source, Argonne National Lab

  • Martin Greven

    • School of Physics and Astronomy, University of Minnesota
    • University of Minnesota
    • School of Physics & Astronomy, University of Minnesota

  • Chris Leighton

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