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