Magnetic Structure of the Heavy-fermion Compound CeAuSb$_2$ in Zero-field

ORAL

Abstract

We have used neutron diffraction to determine the zero-field magnetic structure of the heavy-fermion compound CeAuSb$_2$. Below T$_N\approx 6.2$K, we observe the development of antiferromagnetic Bragg diffraction consistent with previous transport and magnetization measurements. The intensities observed at 7 magnetic satellite locations indicate the staggered magnetization is predominantly along the c-axis. The maximum moment size is $1.15\pm 0.08~\mu_B$ which is large compared with the $0.4~\mu_B$ moment in the iso-structural heavy fermion ferromagnet CeAgSb$_2$. This suggests that the antiferromagnetic CeAuSb$_2$ is deeper into a magnetic phase. The spin structure, due mainly to the Ce-4f sites, is described as a transverse polarized spin density wave with an incommensurate component of the wave vector in the basal plane. We will discuss these results and bulk measurements in terms of an ANNNI model and effective near neighbor exchange interactions.

*The work at IQM was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Material Sciences and Engineering under Grant No. DE-FG02-08ER46544. GGM also acknowledges support from the NSF-GRFP Grant No. DGE-1232825.

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Authors

  • Guy G. Marcus

    • Institute for Quantum Matter and Johns Hopkins University

  • D. J. Kim

    • University of California at Irvine
    • Dept. of Physics and Astronomy, University of California, Irvine
    • University of California, Irvine

  • Hannoh Lee

    • University of California at Irvine

  • Zachary Fisk

    • University of California at Irvine
    • Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA
    • University of California, Irvine

  • J.A. Rodriguez-Rivera

    • NIST Center for Neutron Research
    • NIST

  • C.L. Broholm

    • Johns Hopkins University
    • Institute for Quantum Matter, Johns Hopkins University, and NIST Center for Neutron Research
    • IQM, NIST, Johns Hopkins University