First Experimental Evidence of Potassium Ordering in Layered K4Co7O14
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- 作者：Maxime Blangero ; Rodolphe Decourt ; Dany Carlier ; Gerbrand Ceder ; Michael Pollet ; Jean-Pierre Doumerc ; Jacques Darriet ; and Claude Delmas
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：December 12, 2005
- 年：2005
- 卷：44
- 期：25
- 页码：9299 - 9304
- 全文大小：349K
- 年卷期：v.44,no.25(December 12, 2005)
- ISSN：1520-510X
文摘
The layered P2-KB>4Co7O14 oxide has been prepared and characterized by means of X-ray diffraction, electricalconductivity, thermopower, and magnetic measurements. The crystal structure of K4Co7O14 (P63/m space group, Z= 2, a = 7.5171(1) Å, and c = 12.371(1) Å) consists of a stacking of slabs of edge-shared CoO6 octahedra withK+ ions occupying ordered positions in the interslab space, leading to a a0
7 × a07 supercell. Potential energycalculations at 0 K are in good agreement with the ordered distribution of potassium ions in the (ab) plane. Thisoxide is metallic, and the magnetic susceptibility is of Pauli-type, which contrasts with the Curie-Weiss behaviorof the homologous NaxCoO2 (x 
0.6) oxide with close alkali content. The thermopower at room temperature isabout one-third that of polycrystalline Na0.6CoO2.
7 × a07 supercell. Potential energycalculations at 0 K are in good agreement with the ordered distribution of potassium ions in the (ab) plane. Thisoxide is metallic, and the magnetic susceptibility is of Pauli-type, which contrasts with the Curie-Weiss behaviorof the homologous NaxCoO2 (x 0.6) oxide with close alkali content. The thermopower at room temperature isabout one-third that of polycrystalline Na0.6CoO2.