通过中子衍射和X射线吸收光谱学进行的氧气中介化成SrCoO2.5的时间解析实地研究,采用中子衍射和X射线吸收光谱学
Ronan Le Toquin1, Werner Paulus, Alain Cousson
1Université de Rennes 1: Sciences Chimiques de Rennes, UMR-6226 Inorganic Materials: Soft Chemistry and Reactivity of Solids, F-35042 Rennes, France.
Journal of the American Chemical Society
|October 5, 2006
概括
电化学氧化SrCoO ((2.5) 到SrCoO ((3) 显示了3D氧气排序的中间阶段. 的价值变化是不连续的,表明在这种介质反应中形成O(-) 物种.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 电化学 电化学 电化学
背景情况:
- SrCoO(2.5) 呈现出一种抗铁磁的棕米勒岩结构.
- SrCoO ((3) 是一个具有矿结构的立方铁磁体.
- 了解电化学氧化途径对于材料设计至关重要.
研究的目的:
- 为了研究SrCoO的电化学氧化在现场SrCoO{2.5) 到SrCoO{3).
- 描述氧气间隙过程中的中间阶段和结构/磁性变化.
- 为了确定的价值状态的演变.
主要方法:
- 在现场中子衍射与两个不同的波长.
- 在位X射线吸收细结构 (XAFS) 光谱在Co吸收边缘.
- 设计用于现场分析的电化学电池.
主要成果:
- 确定了两个中间阶段,SrCoO ((2.75) 和SrCoO ((2.82)) ((+/-) ((0.07).
- 在氧气间隔过程中,第一次观察了 SrCoO ((2.82)) ((+/-) ((0.07) 中的3D氧气排序.
- 的价值演变是不连续的,有证据表明O-) 物种的形成.
结论:
- 氧介质反应通过有序氧的明显的中间阶段进行.
- 结构演变证实了顶点的反应机制.
- 在现场中子衍射和XAFS是探测电化学反应过程中散体性质的强大工具.
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