在Ruddlesden-Popper化合物Gd3Ba2Fe4O12.5中的八面体旋转变化是由拓上引入的氧化物离子引起的
Daisuke Urushihara1, Ariki Nakamura1, Kenta Nakajima1
1Division of Advanced Ceramics, Nagoya Institute of Technology, Nagoya 466-8555, Japan.
Inorganic chemistry
|May 6, 2025
概括
通过顶点反应合成Gd3Ba2Fe4O12.5引入了氧化离子,改变了晶体对称性和铁协调. 本研究详细介绍了这种Ruddlesden-Popper化合物的结构和协调变化.
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:
- 拉德尔斯登-波珀化合物以其多样化的结构和电子特性而闻名.
- 了解非静态度对晶体结构的影响对于材料设计至关重要.
- Gd3Ba2Fe4O12 作为探索新氧化物相的前体.
研究的目的:
- 为了合成和表征A位子排序的Ruddlesden-Popper化合物Gd3Ba2Fe4O12.5.5.5.
- 研究将氧化物离子引入Gd3Ba2Fe4O12网格中的结构后果.
- 阐明铁的协调环境和多面体旋转模式的变化.
主要方法:
- Gd3Ba2Fe4O12的拓性化学反应.
- 单晶X射线衍射用于结晶结构的确定.
- 扫描传输电子显微镜 (STEM) 用于结构分析.
- 莫斯巴乌尔光谱法用于识别铁位点.
主要成果:
- Gd3Ba2Fe4O12.5被合成并结晶在一个四角形单元细胞中 (P4(2) /mnm对称).
- 引入的氧化物离子占据了Gd层的一半位置,导致六和五坐标铁位点 (FeO6和FeO5) 的随机分布.
- 莫斯巴乌尔光谱学证实了三个不同的三价Fe位点 (两个FeO6,一个FeO5).
- 多面体旋转模式与<110>方向相比,从同一个方向转移到相反的方向.
结论:
- 氧化物离子在Gd层的Gd3Ba2Fe4O12中占据,导致晶体对称性发生变化.
- 这种对称性变化直接与八面体旋转模式和铁协调环境的变化有关.
- 这项研究强调了Ruddlesden-Popper结构对间歇性氧气结合的敏感性.
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