Thermal and magnetic properties of a low-temperature antiferromagnet Ce$_4$Pt$_{12}$Sn$_{25}$

ORAL

Abstract

We report specific heat ($C$) and magnetization ($M$) of single crystalline Ce$_4$Pt$_{12}$Sn$_{25}$ at temperature down to $\sim$\,50\,mK and in fields up to 3\,T. $C/T$ exhibits a sharp anomaly at 180\,mK, with a large $\Delta$$C$/$T$\,$\sim$\,30\,J/mol\,K$^2$-Ce, which, together with corresponding the cusp-like magnetization anomaly, indicate antiferromagnetic (AFM) ground state with N\'eel temperature $T_{\mathrm{N}}$\,=\,0.18\,K. Numerical calculations based on Heisenberg model reproduce both specific heat and magnetization data, and point to a very small Kondo scale $T_K$, clearly placing Ce$_4$Pt$_{12}$Sn$_{25}$ in the weak exchange coupling $J < J_c$ limit of the Doniac diagram. Magnetic field suppresses AFM state at $H^* \approx 0.7$ T. Anomalous behavior observed in $M$($H$) vs. $T$ for fields in the vicinity of $H^*$ points to a likely field-induced quantum critical point (QCP) at $H^*$.

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Authors

  • R. Movshovich

    • Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • N. Kurita

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • H.-O. Lee

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • Y. Tokiwa

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • C.F. Miclea

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • Eric D. Bauer

    • Los Alamos National Laboratory, New Mexico, USA
    • Los Alamos National Laboratory
    • LANL
    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
    • Los Alamos National Lab

  • F. Ronning

    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • J.D. Thompson

    • Los Alamos National Laboratory
    • LANL
    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • P. Ho

    • Department of Physics, California State University, Fresno, Fresno, California 93740

  • M. B. Maple

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

  • P. Sengupta

    • National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA

  • I. Vekhter

    • Louisiana State University
    • Department of Physics \& Astronomy, Louisiana State University, Baton Rouge, LA 70803
    • Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA

  • Z. Fisk

    • University of California - Irvine
    • University of California Irvine
    • UC Irvine
    • University of California, Irvine, California 92697, USA