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Magnetic Ordering in the Spin-Ice Candidate Ho$_2$Ru$_2$O$_7$

C. R. Wiebe·J. S. Gardner·S. -J. Kim·G. M. Luke·A. S. Wills·B. D. Gaulin·J. E. Greedan·I. Swainson·Y. Qiu·C. Jones
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Abstract

Neutron scattering measurements on the spin-ice candidate material Ho$_2$Ru$_2$O$_7$ have revealed two magnetic transitions at T $\sim$ 95 K and T $\sim$ 1.4 K to long-range ordered states involving the Ru and Ho sublattices, respectively. Between these transitions, the Ho$^{3+}$ moments form short-ranged ordered spin clusters. The internal field provided by the ordered S=1 Ru$^{4+}$ moments disrupts the fragile spin-ice state and drives the Ho$^{3+}$ moments to order. We have directly measured a slight shift in the Ho$^{3+}$ crystal field levels at 95 K from the Ru ordering.

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C. R. Wiebe, J. S. Gardner, S. -J. Kim, G. M. Luke, A. S. Wills, B. D. Gaulin, J. E. Greedan, I. Swainson, Y. Qiu, C. Jones. 2004-04-09. Magnetic Ordering in the Spin-Ice Candidate Ho$_2$Ru$_2$O$_7$. https://doi.org/10.1103/physrevlett.93.076403

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