Thermodynamic and magnetic studies of novel spin ice materials

ORAL

Abstract

We report systematic low temperature measurements of the dc magnetization, ac susceptibility, and heat capacity of $Dy_{2}Sn_{2-x}Sb_{x}O_{7+x/2}$ (x=0, 0.25, and 0.5), and $Dy_{2}NbScO_{7}$. We find evidence for Ising-like single ion ground states in the $Dy_{2}Sn_{2-x}Sb_{x}O_{7+x/2}$ materials, and these materials possess nearly the same zero-point entropy as the canonical spin ices $Ho_{2}Ti_{2}O_{7}$ and $Dy_{2}Ti_{2}O_{7}$. These results strongly suggest that the $Dy_{2}Sn_{2-x}Sb_{x}O_{7+x/2}$ materials studied have spin-ice states at low temperatures despite the cation disorder on the B sites of the pyrochlore lattice We also observe a somewhat reduced zero-point entropy in $Dy_{2}NbScO_{7}$, which is possibly associated with a higher level of cation disorder

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Authors

  • M.L. Dahlberg

    Department of Physics and Materials Research Institute, Pennsylvania State University

  • X. Ke

    The Penn State Univ., Department of Physics and Materials Research Institute, Pennsylvania State University

  • B.G. Ueland

    Department of Physics and Materials Research Institute, Pennsylvania State University, NIST Center for Neutron Research, Gaithersburg MD 20899

  • P. Schiffer

    Dept. of Physics and Materials Research Institute, Pennsylvania State University, Department of Physics, Penn State University, Department of Physics and Materials Research Institute, Pennsylvania State University

  • D.V. West

    Department of Chemistry and Princeton Materials Institute, Princeton University

  • R.J. Cava

    Department of Chemistry and Princeton Materials Institute, Princeton University