Cd and Sn doping effects on Pauli limiting and HFLT state in CeCoIn$_5$

ORAL

Abstract

We investigated the effect of Cd and Sn doping on the superconducting (SC) transition temperature $T_c$, the superconducting critical field $H_{c2}$, and the High-Field-Low- Temperature (HFLT) phase in heavy fermion superconductor CeCoIn$_5$. $T_c$ decreases monotonically for both dopants, whereas $H_{c2}$ rises initially with Cd substitution, while dropping for Sn doping. Analysis of the magnetization data suggests that these effects are caused by weakening of the Pauli limiting in CeCoIn$_5$ with Cd doping, most likely due to changes of susceptibility of the normal state. Both Cd (leading to AFM ground state at higher concentrations) and Sn impurities, at a very low level of a few hundred ppm, suppress the HFLT phase. We interpret these results as supporting the superconducting origin of the HFLT phase.

*Work at Los Alamos National Laboratory was performed under the auspices of the U.S. Department of Energy.

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Authors

  • R. Movshovich

    • Los Alamos National Laboratory
    • LANL, Los Alamas, NM, USA
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • Y. Tokiwa

    • Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • N. Kurita

    • Los Alamos National Laboratory
    • LANL, Los Alamas, NM, USA
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • F. Ronning

    • Los Alamos National Laboratory
    • LANL, Los Alamas, NM, USA
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • E.D. Bauer

    • Los Alamos National Laboratory
    • Los Alamos Natl. Lab., NM, USA
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • P. Papin

    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • J.D. Thompson

    • Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, NM 87544, USA

  • A.D. Bianchi

    • University of Montreal, Montreal, QC, H3C 3J7 Canada

  • J.F. Rauscher

    • University of California, Davis, California 95616, USA

  • S.M. Kauzlarich

    • University of California, Davis, California 95616, USA

  • Z. Fisk

    • Dept. Phys. \& Astro. U. of California, Irvine
    • University of California, Davis, California 95616, USA

  • I. Vekhter

    • Lousiana State University, Baton Rouge, Louisiana 70803, USA