Spin Effects Making zT > 1

ORAL

Abstract

Recent studies of thermoelectric properties of the antiferromagnetic MnTe:Li have revealed the existence of a strong spin effect that extends across a broad range of temperature leading to zT>1 [1,2]. While carrier mobility and heat capacity were strongly affected by spin contributions near the Neel temperature, TN=307K, the thermopower demonstrated robust spin effects extending up to 900K. Spin contribution to those properties below TN has been attributed to the magnon-drag effect [3]. A recent study [2] attributed the thermopower enhancement to paramagnon-drag effect originated from the mid or short-range magnetic ordering above TN. Neutron scattering study showed an agreement to that theory to some extent while some competing theories such as the spin-fluctuations and spin entropy can also explain thermopower enhancement in magnetic materials [1,4]. The objective of this work is to show the agreements and disagreements of different spin-based theories in describing the transport properties of MnTe:Li and to compare similar material systems to gain better insight to the underlying physics.
[1] Vashaee, D., et al., Spin-Cal. IX, June 2018
[2] Yuanhua, Z., et al., Am. Phys. Soc., March 2018
[3] Wasscher, J. D., Phys. Lett. 8, 302-304,1964
[4] Gratz, E., Physica B 237-238, 1997

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Presenters

  • Daryoosh Vashaee

    Department of Electrical and Computer Engineering, North Carolina State University, North Carolina State University

Authors

  • Daryoosh Vashaee

    Department of Electrical and Computer Engineering, North Carolina State University, North Carolina State University

  • Md Mobarak Hossain Polash

    Department of Materials Science and Engineering, North Carolina State University, North Carolina State University

  • Vladislav Perelygin

    Department of Chemistry, North Carolina State University

  • Morteza Rasoulianboroujeni

    Department of Developmental Science, Marquette University, North Carolina State University

  • Yuanhua Zheng

    Department of Mechanical and Aerospace Engineering, The Ohio State University, Ohio State University

  • Tianqi Lu

    Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Institute of Physics, Chinese Academy of Sciences

  • Ning Liu

    Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Institute of Physics, Chinese Academy of Sciences

  • 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

  • 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

  • Alex I Smirnov

    Department of Chemistry, North Carolina State University, North Carolina State University

  • 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

  • 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