Thermal conductivity of KFe<sub>2</sub>As<sub>2</sub> crystals in precisely oriented vector magnetic fields

ORAL

Abstract

Temperature and magnetic field dependent thermal conductivity, κ(T,H), was measured in high quality single crystals of KFe2As2 in precisely oriented magnetic fields in 2D vector magnet for current along the tetragonal b-direction. For fields along a- and c-tetragonal axes we observed monotonic quasi-linear increase of κ(H) followed by a rapid step-wise increase towards the upper critical field, Hc2, consistent with expectations for clean nodal superconductors. Anomalous, increase of κ(T)/T on cooling is found in H∥a configuration for magnetic fields just below Hc2=5 T. These observations are contrasted with the previous heat capacity measurements.

*Novel thermal conductivity unit design used in this study was supported by LDRD grant from Ames laboratory.
This work was supported by the US DOE, Office of Science, BES Materials Science and Engineering Division under contract # DE-AC02-07CH11358.

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Presenters

  • Makariy Tanatar

    • Ames Laboratory

Authors

  • Makariy Tanatar

    • Ames Laboratory

  • Erik Timmons

    • Iowa State University and Ames Laboratory
    • Ames Laboratory and Department of Physics & Astronomy, Iowa State University
    • Ames Laboratory
    • Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University

  • Yong Liu

    • Ames Laboratory and Department of Physics & Astronomy, Iowa State University
    • Ames Laboratory

  • T. A. Lograsso

    • Ames Laboratory and Department of Physics & Astronomy, Iowa State University
    • Ames Laboratory
    • Ames Laboratory, Iowa State University

  • Ruslan Prozorov

    • Ames Lab
    • Iowa State University and Ames Laboratory
    • Ames Laboratory and Department of Physics & Astronomy, Iowa State University
    • Ames Laboratory
    • Ames Laboratory and Iowa state University
    • Ames Laboratory U.S. DOE and Department of Physics and Astronomy, Iowa State University

  • Volodymyr Bondarenko

    • Ames Laboratory

  • Tristin Metz

    • Univ of Maryland-College Park
    • Department of Physics, University of Maryland
    • Center for Nanophysics and Advanced Materials, University of Maryland

  • Johnpierre Paglione

    • Center for Nanophysics and Advanced Materials , University of Maryland
    • CNAM, Department of Physics, University of Maryland
    • Univ of Maryland-College Park
    • Department of Physics, University of Maryland
    • CNAM, Department of Physics, Univ of Maryland-College Park
    • Univ of Maryland - College Park
    • College Park, MD 20742-4111, Univ of Maryland-College Park
    • Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland
    • Center for Nanophysics and Advanced Materials, University of Maryland
    • University of Maryland, College Park
    • University of Maryland