Nonstoichiometry and defect structure of spinel LiMn2O4-δ
Nonstoichiometry and defect structure of spinel LiMn2O4-δ
复制标题
尖晶石LiMn2O4-δ的非化学计量及缺陷结构
DOI：
10.1016/s0378-7753(96)02595-5
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发表时间：
1997
影响因子：
9.2
通讯作者：
N. Kamegashira
中科院分区：
文献类型：
--
作者：
J. Sugiyama;T. Atsumi;T. Hioki;S. Noda;N. Kamegashira
使用热重和化学滴定分析，在 873–1123 K 温度范围内，确定了尖晶石 LiMn2O4 − δ 样品的氧非化学计量 δ 与氧分压 pO2 的函数关系。 LiMn2O4 - δ 的最大氧缺乏度为 δcr= ∼0.2。对于在1023 K获得的样品，随着δ从0增加，在δ=0.07附近出现四方尖晶石相，而对于δ≤0.07的样品仅观察到立方尖晶石相。 δ 对 pO2 的依赖性表示为 δ = ∼pO2(−0.67 ± 0.06)。为了解释这种关系，我们采用了由四个 Mn3+ 离子和两个氧空位组成的缺陷簇模型。另一方面，发现δ=0.67的样品分解为LiMnO2和Mn3O4。
The oxygen nonstoichiometry, δ, has been determined for a spinel LiMn2O4 − δsample as a function of oxygen partial pressure pO2in the 873–1123 K temperature range, using thermogravimetric and chemical titration analysis. The maximum oxygen deficiency of LiMn2O4 − δwas found to be δcr= ∼0.2. For the samples obtained at 1023 K, as δ increased from 0, the tetragonal spinel phase appeared around δ = 0.07, while only the cubic spinel phase was observed for the samples with δ ≤ 0.07. The dependence of δ on pO2was expressed as δ = ∼pO2(−0.67 ± 0.06). In order to explain this relation, we employed a defect cluster model consisting of four Mn3+ions and two oxygen vacancies. On the other hand, the sample with δ = 0.67 was found to decompose to LiMnO2and Mn3O4.