阳离子促进的阴离子运动和传导在热石中
Edgar Jordan1, Robert G Bell, Dirk Wilmer
1Institute of Physical Chemistry and Sonderforschungsbereich 458, University of Münster, Germany.
Journal of the American Chemical Society
|January 13, 2006
概括
阳离子相互作用促进酸盐在 sodalite 和 cancrinite 的运动,但合作性是导电性的关键. 化离子降低激活障碍,而较大的离子增加它们.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 交通运输 交通运输 交通运输
背景情况:
- 酸盐和酸盐框架中的酸盐流动性对于它们的离子导电性至关重要.
- 了解阴离子对阴离子动态的影响对于设计先进材料至关重要.
研究的目的:
- 为了研究酸盐在 sodalite 和 cancrinite 的运动.
- 为了确定各种离子对离子移动性和导电性的特定影响.
- 探索局部阳离子运动和远程离子传输之间的关系.
主要方法:
- 力量场计算以确定局部运动的激活障碍.
- 固态核磁共振 ((23) Na NMR) 光谱检测离子动态.
- 阻抗光谱测量直流电导率并评估远距离传输.
主要成果:
- 局部离子运动通过与阴离子的相互作用而增强.
- 化物离子 (Cl-, Br-, I-) 降低了石中的激活障碍,而障碍随着离子大小的增加而增加.
- 在低于470K的密集石中观察到刚性离子;在染色石和 cancrinite epsilon-cages中观察到限制运动.
- 在cancrinite的开放通道中,Na+在染色体离子附近的选择性高局部运动.
结论:
- 阳离子相互作用可以选择性地增强局部迁移,特别是在开放通道系统中.
- 阴离子运动的合作性是实现良好的整体离子导电性的关键因素,而不仅仅是局部的移动性.
- 没有观察到离子重定向和离子运动之间的动态合.
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