Dynamics of water in theNa0.3CoO2∙1.4H2Osuperconductor
| Autor: | Eugene Mamontov, L. Viciu, V. García Sakai, J. W. Lynn, Robert J. Cava |
|---|---|
| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Physical Review B. 75 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.75.014505 |
| Popis: | The 4.3 K superconductor Na0.3CoO2 · 1.4H2O has been well studied since its discovery 1 because it may be a new type of superconductor based on magnetic interactions. Though other layered superconductors such as NaxTaS2 are known to remain superconducting even when water is intercalated between the layers, 2 the cobalt oxyhydrate is unique in that the intercalated water is required to induce the superconductivity. The water acts primarily as a spacer, increasing the interplane CoO2 spacing from 5 A to 9 A on going from Na 0.3 CoO 2 to Na 0.3 CoO 2 · 1.4H 2 O, therefore enhancing the two-dimensional character of the electronic system. The intercalation process also has an impact on the thickness of the CoO2 plane, suggesting that water may act as more than a spacer, possibly as a dielectric. 3 No molecules other than water have been reported to intercalate between the layers of Na0.3CoO2. The character of the water within the layers remains an open question. Here we report the results of quasielastic neutron scattering measurements designed to characterize the dynamics of the water molecules. The results show that the water behaves like the water strongly confined in pores, with only highly limited diffusive transport present. No anomaly is seen in the dynamics of the water motion at the superconducting transition temperature suggesting that molecular water vibrations are not strongly involved in the superconducting mechanism. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|