Evidence fors-wave superconductivity in theβ-pyrochlore oxideRbOs2O6
| Autor: | J. L. Gavilano, H. R. Ott, J. Hinderer, J. Karpinski, Sergey M. Kazakov, M. Weller, B. Pedrini, K. Magishi |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Physical Review B. 71 |
| ISSN: | 1550-235X 1098-0121 |
| Popis: | We report the results of $^{87}\mathrm{Rb}$ NMR measurements on ${\mathrm{RbOs}}_{2}{\mathrm{O}}_{6}$, a member of the family of the superconducting pyrochlore-type oxides with a critical temperature ${T}_{c}=6.4\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. In the normal state, the nuclear spin-lattice relaxation time ${T}_{1}$ obeys the Korringa-type relation ${T}_{1}T=\mathrm{const}$ and the Knight shift is independent of temperature, indicating the absence of strong magnetic correlations. In the superconducting state, ${T}_{1}^{\ensuremath{-}1}(T)$ exhibits a tiny coherence enhancement just below ${T}_{c}$, and decreases exponentially with further decreasing temperatures. The value of the corresponding energy gap is close to that predicted by the conventional weak-coupling BCS theory. Our results indicate that ${\mathrm{RbOs}}_{2}{\mathrm{O}}_{6}$ is a conventional $s$-wave-type superconductor. |
| Databáze: | OpenAIRE |
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