Suppression of Pauling's Residual Entropy in Dilute Spin Ice (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$
Suppression of Pauling's Residual Entropy in Dilute Spin Ice (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$
复制标题
稀旋转冰中鲍林残余熵的抑制 (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$
DOI：
10.1103/physrevb.92.180405
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发表时间：
2015
影响因子：
3.7
通讯作者：
T. Lorenz
中科院分区：
文献类型：
--
作者：
S. Scharffe;O. Breunig;V. Cho;P. Laschitzky;M. Valldor;J.F. Welter;T. Lorenz
在0.5 K左右，自旋冰的熵具有类似于平台的特征，接近最初为水冰导出的鲍林剩余熵，但超低热平衡阻止了对较低温度的明确量化。根据比热数据，分析了非磁稀释对低温熵的影响。随着温度的增加，超低热平衡迅速消失，低温熵系统地减小，其温度依赖性强。这些数据表明，在中间稀释中实现了非简并基态。这与鲍林理论对稀自旋冰的推广所期望的零温度剩余熵相矛盾，但得到了蒙特卡罗模拟的支持。
Around 0.5 K, the entropy of the spin icehas a plateaulike feature close to Pauling's residual entropy derived originally for water ice, but an unambiguous quantification towards lower temperature is prevented by ultraslow thermal equilibration. Based on the specific-heat data ofwe analyze the influence of nonmagnetic dilution on the low-temperature entropy. With increasing, the ultraslow thermal equilibration rapidly vanishes, the low-temperature entropy systematically decreases, and its temperature dependence strongly increases. These data suggest that a nondegenerate ground state is realized infor intermediate dilution. This contradicts the expected zero-temperature residual entropy obtained from a generalization of Pauling's theory for dilute spin ice, but is supported by Monte Carlo simulations.