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.

–

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