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;