資料載入中.....
|
請使用永久網址來引用或連結此文件:
http://ir.ncue.edu.tw/ir/handle/987654321/14120
|
| 題名: | Synthesis and Characterization of Layered Sodium Cobaltates |
| 作者: | Liu, Chia-Jyi |
| 貢獻者: | 物理學系 |
| 日期: | 2011
|
| 上傳時間: | 2012-09-10T06:12:20Z
|
| 出版者: | Nova Science Publishers |
| 摘要: | The layered sodium cobaltates -NaxCoO2 show low electrical conductivity and large thermopower. These features are required for candidate materials in thermoelectric applications. Superconductive sodium cobalt oxyhydrates can be obtained by topotactic transformation of -NaxCoO2 via oxidative de-intercalation and hydration. This chapter presents the synthesis of -Na0.7CoO2 in the form of sol-gel bulk, films, nanotubules and submicron tubules. Materials characterization of -NaxCoO2 and cobalt oxyhydrates will be also presented. According to thermopower analysis, band narrowing is observed when -Na0.7CoO2 is transformed to potassium sodium cobaltoxyhydrates. According to the Co K-edge x-ray absorption spectra, the Co oxidation number for bi-layer hydrate Na0.33K0.02(H2O)1.33CoO2 is higher than that of mono-layer hydrate Na0.07K0.21 (H2O)0.63CoO2 with a chemical shift of 3.5 eV, which is in sharp contrast with Co K-edge x-ray absorption spectroscopy and cerimetric titration results for Nax(H2O)yCoO2, where there is essentially no difference of the oxidation number of Co between bi-layer and mono-layer sodium cobalt oxyhydrates. |
| 關聯: | 收錄於由 Lucas J. Vidmar 主編「Cobalt: Characteristics, Compounds and Applications」, Chapter 11: 227-262 |
| 顯示於類別: | [物理學系] 專書
|
在NCUEIR中所有的資料項目都受到原著作權保護.
|
