Chemical instability of the cobalt oxyhydrate superconductor under ambient conditions

✍ Scribed by M.L. Foo; R.E. Schaak; V.L. Miller; T. Klimczuk; N.S. Rogado; Y. Wang; G.C. Lau; C. Craley; H.W. Zandbergen; N.P. Ong; R.J. Cava

• Book ID: 104166165
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 242 KB
• Volume: 127
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/s0038-1098(03)00334-x

✦ Synopsis

The layered sodium cobalt oxyhydrate superconductor Na 0.3 CoO 2 •1.4H 2 O is shown through X-ray diffraction and thermogravimetric studies to be one of the series of hydrated phases of Na 0.3 CoO 2 . Further, it is shown that the material is exceptionally sensitive to both temperature and humidity near ambient conditions, easily dehydrating to a non-superconducting lower hydrate. The observation of this stable lower hydrate with c ¼ 13:8

A implies that the superconductivity turns on in this system between CoO 2 layer spacings of 6.9 and 9.9 A ˚at nominally constant chemical doping.