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.

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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