Magneto-thermoelectric effect in lanthanum orthoferrite with Pt overlayer

ORAL

Abstract

Spin caloritronic phenomena, utilizing heat flow to transport spin signals with minimal or no charge current, are of fundamental interest with important applications. We have observed nontrivial magneto-thermoelectric effects in lanthanum orthoferrite (LaFeO3) perovskite single crystals with Pt overlayer at room temperature. The LaFeO3 is a canted antiferromagnetic insulator with weak magnetization of about 0.04 μB per Fe atom along the c-axis, which is only 1% of that of the common ferromagnet iron. The amplitude of magneto-thermovoltage in the Pt/LaFeO3 with an in-plane temperature gradient is comparable to those of the longitudinal spin Seebeck effect and inverse spin Hall effect in Pt/yttrium iron garnet. It provides a sensitive probe of very weak magnetization in the insulator, which can be manipulated by a magnetic field of the order of 10 mT. However, from the thermoelectric measurement configurations and the angular dependence on the applied magnetic field, our results are distinctly different from those of the anomalous Nernst effect and longitudinal spin Seebeck effect. We attribute our results to a thermal magnon transport at the Pt/LaFeO3 interface.

**This work was supported by National Science Foundation DMREF, Grants No. 1729555 and 1729588, and DMR-1949701.

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Presenters

  • Weiwei Lin

    • Department of Physics and Astronomy, Johns Hopkins University

Authors

  • Weiwei Lin

    • Department of Physics and Astronomy, Johns Hopkins University

  • Jiaming He

    • Department of Mechanical Engineering, University of Texas at Austin
    • Materials Science and Engineering program, Department of Mechanical Engineering, University of Texas at Austin

  • Jianshi Zhou

    • Geological Sciences, University of Texas at Austin
    • Department of Mechanical Engineering, The University of Texas at Austin
    • Walker Department of Mechanical Engineering, University of Texas at Austin
    • Department of Mechanical Engineering, University of Texas at Austin
    • The University of Texas at Austin
    • University of Texas at Austin
    • University of Texas
    • Materials Science and Engineering program, Department of Mechanical Engineering, University of Texas at Austin

  • Bowen Ma

    • Department of Physics, University of Texas at Austin
    • University of Texas at Austin

  • Gregory A Fiete

    • University of Texas at Austin
    • Northeastern University
    • Department of Physics, Northeastern University

  • Chia-Ling Chien

    • Department of Physics and Astronomy, Johns Hopkins University
    • Johns Hopkins University