Possible interface induced superconductivity in un-doped CaFe<sub>2</sub>As<sub>2</sub>

ORAL

Abstract

The superconductivity with a Tc up to 25 K was induced through a proper annealing process in un-doped CaFe2As2. A series of low temperature X-ray diffraction (LTXRD) studies were carried out and we found that the emergence of superconductivity is closely tied to the mixture of the PI and PII phases of CaFe2As2. The experimental results indicate that the origin of superconductivity arises from the interface of the mesoscopically stacked layers of PI and PII. Using negative binomial distribution, we simulated the possible phase distribution of samples under different thermal treatments. The simulation results are consistent with the LTXRD data. These simulations were further supported by low temperature scanning transmission electron microscopy (LTSTEM) measurements. The LTXRD, LTSTEM, and simulation results we shall present strongly support the proposal of interface-enhanced superconductivity in un-doped CaFe2As2.

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Presenters

  • Shuyuan Huyan

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

Authors

  • Shuyuan Huyan

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

  • Liangzi Deng

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

  • Kui Zhao

    • Texas Center for Superconductivity
    • Department of Physics and Texas Center for Superconductivity, University of Houston

  • Jingying Sun

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

  • Zheng Wu

    • Department of Physics and Texas Center for Superconductivity, University of Houston
    • TcSUH and Dept. of Physics, University of Houston
    • Department of Physics and Texas Center for Superconductivity at University of Houston

  • Lijun Wu

    • Condensed Matter Physcis and Materials Science Departement, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Brookhaven Natl Lab

  • Melissa Gooch

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

  • Bing Lv

    • University of Texas at Dallas
    • Department of Physics, University of Texas at Dallas
    • Univ of Texas, Dallas
    • Dept. of Physics, The University of Texas at Dallas
    • Department of Physcis, University of Texas at Dallas

  • Shuo Chen

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

  • Yimei Zhu

    • Condensed Matter Physcis and Materials Science Departement, Brookhaven National Laboratory
    • Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science, Brookhaven National Laboratory
    • Brookhaven Natl Lab
    • Brookhaven National Lab
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory

  • Paul Chu

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