Pressure-induced shift of $T_c $ in $K_x Sr_{1-x} Fe_2 As_2 $ (x = 0.2, 0.4, 0.7): Analogy to the high-T$_{c}$ cuprate superconductors

ORAL

Abstract

Through a systematic study of $K_x Sr_{1-x} Fe_2 As_2 $ (x = 0.2, 0.4, 0.7), by pressure shifts of the $T_c $, similarities between the FeAs and high T$_{c}$ superconductors can be observed. These similarities develop directly from the layered structure seen in both superconductors, which consists of an active superconducting layer and a charge reservoir block. The pressure coefficient of Tc depends on the doping level: dTc/dp$>$0 (underdoped, x=0.2), dTc/dp=0 (optimally doped, x=0.4), and dTc/dp$<$0 (overdoped, x=0.7). This is understood in terms of a pressure-induced charge transfer between the active and charge reservoir layers. In addition to the measured pressure shift in the T$_{c}$, the suppression of the spin density wave can clearly be demonstrated for the x = 0.2 case.

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Authors

  • Melissa Gooch

    • Texas Center for Superconductivity at the University of Houston and Department of Physics

  • 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

  • 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;