Chemical substitution study on magnetism and superconductivity in Ce$_{1-x}$Sm$_x$CoIn$_5$

ORAL

Abstract

We have investigated the system Ce$_{1-x}$Sm$_x$CoIn$_5$ (0 $<$ $x$ $<$ 1) by means of x-ray diffraction, electrical resistivity, specific heat, and magnetization measurements. We observe a crossover from a coherent Kondo lattice exhibiting superconductivity to a single-ion impurity Kondo effect coexisting with magnetic order on the Sm-rich side of the phase diagram. The superconducting transition temperature, $T_c$, and Kondo lattice coherence temperature, $T_{coh}$, are suppressed near $x$ $\sim$ 0.2 and $x$ $\sim$ 0.5, respectively, which is consistent with the effect of substitution with other rare-earth (RE) ions on CeCoIn$_5$. After $T_{coh}$ is suppressed to 0 K, a single-ion impurity Kondo effect is observed for 0.5 $<$ $x$ $\leq$ 0.85. The compound SmCoIn$_5$ exhibits three distinct magnetic phase transitions at roughly 8, 10, and 12 K, which are presumably associated with magnetic order; similar features are observed in the related compound SmIn$_3$. These transition temperatures are gradually suppressed by Ce substitution and completely vanish near $x$ $\sim$ 0.2. We establish the phase diagram of the system Ce$_{1-x}$Sm$_x$CoIn$_5$ and compare our results with those obtained from chemical substitution studies of CeCoIn$_5$ involving other RE ions.

*Research at UCSD was supported by the U. S. Department of Energy, Office of Basic Energy Science, Division of Material Science and Engineering under Grant No. DE-FG02-04-ER46105

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Authors

  • Sooyoung Jang

    • Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA

  • B. White

    • University of California, San Diego
    • Physics Department, UC San Diego
    • Department of Physics, University of California, San Diego
    • Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA

  • D. Yazici

    • Physics Department, UC San Diego
    • Department of Physics, University of California, San Diego
    • UC, San Diego
    • Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA

  • A.S. Wong

    • Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA

  • Brian Maple

    • University of California, San Diego
    • Physics Department, UC San Diego
    • Department of Physics, University of California, San Diego
    • Physics/UC San Diego
    • Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
    • Department. of Physics, U. of California, San Diego