Water Content and Superconductivity in Na0.3CoO2*yH2O

Abstract

We report here the correlation between the water content and superconductivity in Na0.3CoO2*yH2O under the influences of elevated temperature and cold compression. The x-ray diffraction of the sample annealed at elevated temperatures indicates that intergrowths exist in the compound at equilibrium when 0.6 < y < 1.4. Its low-temperature diamagnetization varies linearly with y, but is insensitive to the intergrowth, indicative of quasi-2D superconductivity. The Tc-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.

arXiv comment10 pages, 10 figures; submitted to Physica C (August 13, 2003)

References in corpus (3)

• Crystal Structure of the Sodium Cobaltate Deuterate Superconductor NaxCoO2o4xD2O (x=1/3)
• Structure and Dynamics of Superconducting NaxCoO(2) Hydrate and Its Unhydrated Analog
• Chemical Instability of the Cobalt Oxyhydrate Superconductor under Ambient Conditions

Cited by in corpus (5)

• Impurity Effects on the Superconducting Transition Temperature of NazCoO2.yH2O
• Study of intercalation and deintercalation of Na_xCoO_2 yH_2O single crystals
• A novel route to phase formation of cobalt oxyhydrates using KMnO4 as an oxidizing agent
• Thermal Expansion and Compressibility in Superconducting NaxCoO2o4xD2O (x?1/3): Evidence for Pressure-Induced Charge Redistribution
• Proton incorporations and superconductivity in a cobalt oxyhydrate