Electrically-induced ferromagnetism in diamagnetic FeS<sub>2</sub>

ORAL

Abstract

Recent years have seen increasingly impressive demonstrations of all-electrical control of magnetism, including electrolyte-gating-induced ferromagnetism in non-ferromagnetic materials. These demonstrations, however, involve induction of ferromagnetism from some other finite-spin magnetic state, e.g., antiferromagnetic, paramagnetic, etc. In this work we use ionic liquid gating, which can induce electron densities >1014 cm-2, to achieve voltage-induced ferromagnetism in diamagnetic (i.e., zero-spin) FeS2 single crystals. Temperature-dependent transport measurements establish a remarkably reversible positive-bias-induced insulator-metal transition, accompanied by inversion of the FeS2 surface conduction channel to n-type. Anomalous Hall effect measurements then reveal an accompanying onset of voltage-induced soft 2D ferromagnetism, with Curie temperature up to ~20 K. These results are supported by DFT-based tight-binding modelling that indicates induction of Stoner FM by gate-controlled band filling.

*Work supported by the NSF MRSEC under DMR-1420013 (UMN) and by a Margaret A. Cargill Philanthropies grant (Augsburg).

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Presenters

  • Jeff Walter

    • Department of Physics, Augsburg University

Authors

  • Jeff Walter

    • Department of Physics, Augsburg University

  • Bryan Voigt

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

  • Ezra Day-Roberts

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

  • Kei Heltemes

    • Department of Physics, Augsburg University

  • Turan Birol

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

  • Rafael Fernandes

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

  • Chris Leighton

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