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).

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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