Unexpected Enhancement of Superconductivity in CeO0.5F0.5BiS2 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.

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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