Spin Dynamics in the Thermoelectric Li:MnTe Antiferromagnetic Semiconductor

ORAL

Abstract

We report the magnetic structure and excitation spectrum of Li0.03:MnTe, a material related to the MnTe antiferromagnetic semiconductor with a Néel temperature of ~307 K. MnTe was proposed to exhibits a strong contribution of magnon drag to the thermopower[1]. Neutron scattering reveals the magnetic structure and spin-spin correlations in the ordered and disordered phases of Li0.03:MnTe. Above the magnetic ordering temperature, strong quasielastic paramagnon scattering is observed. The characteristic energy width of the scattering is temperature independent and provides evidence for slow, ~30 fs, magnetic fluctuations. These data provide necessary input for modelling of the transport properties.
[1] J. D. Wasscher, C. Haas, Contribution of magnon-drag to the thermoelectric power of antiferromagnetic MnTe. Phys. Lett. 8, 302-304 (1964).

*Supported by U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (RPH and MM). This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL).

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Presenters

  • Raphael Hermann

    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge TN-37831-6064, USA

Authors

  • Raphael Hermann

    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge TN-37831-6064, USA

  • Michael Manley

    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge TN-37831-6064, USA

  • Vasile O Garlea

    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6475, USA
    • Neutron Scattering Division, Oak Ridge National Lab

  • Douglas L Abernathy

    • Spallation Neutron Source, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6475, USA

  • Huaizhou Zhao

    • Institute of Physics, Chinese Academy of Sciences
    • Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics
    • Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China

  • Joseph P C Heremans

    • Department of Mechanical and Aerospace Engineering, The Ohio State University
    • Ohio State University
    • Ohio State Univ - Columbus
    • Department of Mechanical Engineering, The Ohio State University
    • Department of Mechanical and Aerospace Engineering, Department of Physics, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA