Sr3Co2O4Cl2的结构和磁性 - - 一种电子驱动的晶格扭曲,在含有正方形平面C0II中心的氧化中
Fabio Denis Romero1, Lucy Coyle, Michael A Hayward
1Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, United Kingdom.
Journal of the American Chemical Society
|August 31, 2012
概括
拓化学还原产生了一种新的合金氧化阶段,Sr(3)Co(2)O(4)Cl(2). 这种材料表现出类似于Jahn-Teller的扭曲和独特的倾斜的反铁磁状态,具有显著的轨道贡献.
科学领域:
- 固态化学 固态化学
- 材料科学是一种材料科学.
- 晶体学 晶体学是指结晶学.
背景情况:
- 合金氧化由于其独特的结构和电子特性而引起人们的兴趣.
- 了解过渡金属氧化物和化物中的结构性质关系对于开发新的功能材料至关重要.
研究的目的:
- 为了合成和表征一种新型的石氧化阶段.
- 研究合成材料的结构,电子和磁性特性.
- 探索电子配置和格子动态之间的关系.
主要方法:
- 在200°C使用NaH进行Sr(3)Co(2)O(5)Cl(2) 的拓化学还原.
- 在各种温度下 (298 K和5 K) 进行结构分析的X射线衍射 (XRD).
- 磁化测量以探测磁性排序和 Moment 的贡献.
主要成果:
- 合成了具有Co (II) O (IV) 方形平面和SrCl层的分层结构的Sr (III) Co (III) Co (III) Co (II) Co (II) Co) Co (II) Co (II) Co (II) Co) Co (II) Co (II) Co (II) Co) Co (II) Co (II) Co) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) Co (II) (II) Co (II) (II) (II) (II)
- 观察到200K以下的结构相从四边形 (I4/mmm) 转变为正角形 (Immm),归因于类似于Jahn-Teller的扭曲.
- 证据表明50K以下的反铁磁倾斜状态,对磁矩有显著的轨道贡献.
结论:
- 新的合金氧化,Sr(3) Co(2) O(4) Cl(2),显示其电子配置和格子结构之间强烈的合.
- 观察到的类似于Jahn-Teller的扭曲凸显了轨道退化在推动结构变化的作用.
- 磁性行为表明了实质性的轨道贡献,超过了Co (II) 中心的简单自旋模型.
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