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Water content and superconductivity in Na0.3CoO2 · yH2O

✍ Scribed by J. Cmaidalka; A. Baikalov; Y.Y. Xue; R.L. Meng; C.W. Chu

Publisher
Elsevier Science
Year
2004
Tongue
English
Weight
481 KB
Volume
403
Category
Article
ISSN
0921-4534

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✦ Synopsis

We report here the correlation between the water content and superconductivity in Na 0:3 CoO 2 AE yH 2 O under the influences of elevated temperature and cold compression. The X-ray diffraction of the sample annealed at elevated temperatures indicates that intergrowths may exist in the compound at equilibrium when 0:6 < y < 1:4. Its low-temperature equilibrium diamagnetization M s varies linearly with y, but is insensitive to the intergrowth, indicative of quasi-2D superconductivity. The T c -onset, especially, shifts only slightly with y. Our data from cold compressed samples, on the other hand, show that the water loss non-proportionally suppresses the diamagnetization, which is suggestive of weak links.

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