Unexpected Enhancement of Superconductivity in CeO<sub>0.5</sub>F<sub>0.5</sub>BiS<sub>2</sub> at 10 GPa

ORAL

Abstract

We report measurements of electrical resistivity as a function of temperature, at pressures up to 20 GPa, on the layered BiS2-based superconducting system LnO0.5F0.5BiS2 (Ln = La, Ce). Under pressure, compounds with Ln = La, Ce, Pr, Nd or Yb exhibit a rapid and pronounced increase in the superconducting transition temperature (Tc) from a low-Tc phase to a higher-Tc phase, followed by a gradual decrease in Tc as pressure is increased. LaO0.5F0.5BiS2 shows an enhancement of Tc from 3.3 K at 0 GPa to 10.1 K at 1.1 GPa followed by a monotonic decrease up to 15 GPa. CeO0.5F0.5BiS2 displays an increase of Tc from 2.3 K at 0 GPa to 6.7 K at 2 GPa. Preliminary results indicate a subsequent enhancement of Tc from 4.7 K at 5.5 GPa to 7.2 K at 10 GPa. This may be associated with a pressure-induced increase in the valence of Ce that electron dopes the BiS2 planes. This is consistent with a previous report on the effect of substituting tetravalent Th, Hf, Zr, or Ti for trivalent La in inducing superconductivity in LaOBiS2. We are performing further measurements to substantiate these results.

*Research supported the NNSA through DOE under DE- NA0002909 (high-pressure measurements), and DOE under DEFG02-04-ER46105 (materials synthesis)

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Presenters

  • Zackary Rehfuss

    • Physics, Univ of California - San Diego

Authors

  • Zackary Rehfuss

    • Physics, Univ of California - San Diego

  • Christian Wolowiec

    • Department of Physics, University of California, San Diego
    • Physics, University of California, San Diego
    • Department of Physics and Center for Advanced Nanoscience, University of California, San Diego
    • Physics, Univ of California - San Diego

  • Yuankan Fang

    • Univ of California - San Diego
    • Materials Science and Engineering Program, Univ of California - San Diego

  • Colin McElroy

    • Physics, Univ of California - San Diego

  • Duygu Yazici

    • Physics, Univ of California - San Diego

  • Kevin Huang

    • National High Magnetic Field Lab, Florida State University
    • NHMFL
    • Natl High Magnetic Field Lab
    • NHMFL at Florida State University
    • National HIgh Magnetic Field Lab at Florida State University
    • National High Magnetic Field Lab at Florida State University
    • State Key Laboratory of Surface Physics, Department of Physics, Fudan University

  • Inho Jeon

    • University of California, San Diego
    • Physics, University of California, San Diego
    • Department of Physics, University of California, San Diego
    • Materials Science and Engineering, University of California, San Diego
    • Materials Science and Engineering Program and Center for Advanced Nanoscience, University of California, San Diego
    • Materials Science and Engineering Program, and Center for Advanced Nanoscience, Univ of California - San Diego
    • Materials Science and Engineering Program, Univ of California - San Diego
    • University of California-San Diego

  • Kalyan Sasmal

    • Department of Physics, University of California, San Diego
    • Physics, University of California, San Diego
    • Physics, Univ of California - San Diego

  • Jason Jeffries

    • Lawrence Livermore National Lab
    • Condensed Matter and Materials Division, Lawrence Livermore National Laboratory
    • LLNL

  • Ryan Stillwell

    • Lawrence Livermore National Lab
    • Condensed Matter and Materials Division, Lawrence Livermore National Laboratory

  • Samuel Weir

    • Lawrence Livermore National Laboratory
    • Condensed Matter and Materials Division, Lawrence Livermore National Laboratory

  • Yogesh Vohra

    • Physics, Univ of Alabama - Birmingham
    • Physics, University of Alabama at Birmingham
    • Physics, Univ of Alabama at Birmingham

  • M Brian Maple

    • Department of Physics, University of California, San Diego
    • University of California, San Diego
    • Physics, University of California, San Diego
    • Univ of California - San Diego
    • Department of Physics and Center for Advanced Nanoscience, University of California, San Diego
    • Department of Physics, Center for Advanced Nanoscience,Materials Science and Engineering Program , Univ of California - San Diego
    • Department of Physics, University of California San Diego
    • Physics, Univ of California - San Diego
    • University of California-San Diego
    • UC San Diego
    • Physics, UC San Diego