Superconducting Fe-Based Compounds (A$_{1-x}$Sr$_{x })$Fe$_{2}$As$_{2}$ with A = K and Cs with Transition Temperatures up to 37 K

ORAL

Abstract

New high-Tc Fe-based superconducting compounds, AFe$_{2}$As$_{2}$ with A = K, Cs, K/Sr, and Cs/Sr, were synthesized. The Tc of KFe$_{2}$As$_{2}$ and CsFe$_{2}$As$_{2}$ is 3.8 and 2.6 K, respectively, which rises with partial substitution of Sr for K and Cs and peaks at 37 K for 50{\%}--60{\%} Sr substitution, and the compounds enter a spin-density-wave state with increasing electron number (Sr content). The compounds represent p-type analogs of the n-doped rare-earth oxypnictide superconductors. Their electronic and structural behavior demonstrate the crucial role of the (Fe$_{2}$As$_{2})$ layers in the superconductivity of the Fe-based layered systems, and the special feature of having elemental A layers provides new avenues to superconductivity at higher Tc.

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Authors

  • Kalyan Sasmal

    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204, USA

  • Bing Lv

    • Texas Center for Superconductivity at the University of Houston and Department of Chemistry
    • TCSUH and Department of Chemistry, University of Houston, Houston, Texas 77204, USA

  • Bernd Lorenz

    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204-5002, USA
    • TCSUH and Dept. of Physics, University of Houston
    • Texas Center for Superconductivity at the University of Houston and Department of Physics
    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204, USA

  • Arnold M. Guloy

    • Dept. of Chemistry, University of Houston, Houston, TX 77204
    • Texas Center for Superconductivity at the University of Houston and Department of Chemistry
    • TCSUH and Department of Chemistry, University of Houston, Houston, Texas 77204, USA

  • Feng Chen

    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204, USA

  • Yu-Yi Xue

    • University of Houston
    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204, USA

  • Ching-Wu Chu

    • University of Houston
    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204-5002, USA
    • Dept. of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5002
    • Texas Center for Superconductivity at the University of Houston; Lawrence Berkeley National Laboratory; Hong Kong University of Science and Technology
    • TCSUH and Department of Physics, University of Houston, Houston, Texas 77204, USA;