2004/12/12 by X. Z. Chen, Chen, X. Z., Z. A. Xu +14
Materials Science · Physics and Astronomy · #Chemical and Physical Properties of Materials #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Theoretical and Computational Physics #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.cond-mat/0412299
9 pages, 5 figures
arxiv created 2004/12/12 · openalex publication_date 2004/12/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Single crystals of Na0.5CoO2 were obtained through a flux method followed by de-intercalation of sodium. The Na0.5CoO2 samples were found to be vulnerable to water in the air and a hydration process in which H2O molecules fill oxygen vacancies in CoO2 layers is suggested to be responsible for the unusual vulnerability to water. The transport properties, including resistivity (ρ), thermopower (S) and Hall coefficient (RH), were studied in a temperature range of 5-300 K. The compound shows a weak localization of carriers just below 200 K and Co3+-Co4+ charge ordering at about 30 K, a relatively lower temperature than previously reported. The results seem to be quite different from those previously reported for this system [Foo et al, Phys. Rev. Lett. 92 (2004) 247001]. Possible mechanism underlying this kind of inconsistency is discussed.