Suppression of Pauling's Residual Entropy in Dilute Spin Ice (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$
| Autor: | Scharffe, S., Breunig, O., Cho, V., Laschitzky, P., Valldor, M., Welter, J. F., Lorenz, T. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Physical Review B 92, 180405(R) (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.92.180405 |
| Popis: | Around 0.5 K, the entropy of the spin-ice Dy$_2$Ti$_2$O$_7$ has a plateau-like feature close to Pauling's residual entropy derived originally for water ice, but an unambiguous quantification towards lower temperature is prevented by ultra-slow thermal equilibration. Based on specific heat data of (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$ we analyze the influence of non-magnetic dilution on the low-temperature entropy. With increasing x, the ultra-slow thermal equilibration rapidly vanishes, the low-temperature entropy systematically decreases and its temperature dependence strongly increases. These data suggest that a non-degenerate ground state is realized in (Dy$_{1-x}$Y$_x$)$_2$Ti$_2$O$_7$ for 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. Comment: 5 pages, 4 figures; slightly revised version to appear in PRB Rapid Communications |
| Databáze: | arXiv |
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