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Spin Correlations in Ho$_{2}$Ti$_{2}$O$_{7}$: a Dipolar Spin Ice System

S. T. Bramwell·M. J. Harris·B. C. den Hertog·M. J. P. Gingras·J. S. Gardner·D. F. McMorrow·A. R. Wildes·A. L. Cornelius·J. D. M. Champion·R. G. Melko·T. Fennell
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Abstract

The pyrochlore material $\rm Ho_{2}Ti_{2}O_{7}$ has been suggested to show ``spin ice'' behaviour. We present neutron scattering and specific heat results that establish unambiguously that Ho$_2$Ti$_2$O$_7$ exhibits spin ice correlations at low temperature. Diffuse magnetic neutron scattering from Ho$_2$Ti$_2$O$_7$ is found to be quite well described by a near neighbour spin ice model and very accurately described by a dipolar spin ice model. The heat capacity is well accounted for by the sum of a dipolar spin ice contribution and an expected nuclear spin contribution, known to exist in other Ho$^{3+}$ salts. These results settle the question of the nature of the low temperature spin correlations in $\rm Ho_{2}Ti_{2}O_{7}$ for which contradictory claims have been made.

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S. T. Bramwell, M. J. Harris, B. C. den Hertog, M. J. P. Gingras, J. S. Gardner, D. F. McMorrow, A. R. Wildes, A. L. Cornelius, J. D. M. Champion, R. G. Melko, T. Fennell. 2001-03-08. Spin Correlations in Ho$_{2}$Ti$_{2}$O$_{7}$: a Dipolar Spin Ice System. https://doi.org/10.1103/physrevlett.87.047205

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