了解混合层矿的结构扭曲,其中具有n = 1的Ruddlesden-Popper结构
Tianyu Liu1, Noah P Holzapfel1, Patrick M Woodward1
1Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
IUCrJ
|June 12, 2023
概括
对称性分析揭示了混合有机-无机分层矿中47种不同的八面体倾斜模式. 大多数结构与预测相匹配,由于离子包装或层移动而有偏差.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 固态化学 固态化学
背景情况:
- 混合有机-无机分层矿是具有可调节性质的关键材料.
- 拉德尔斯登-波珀 (RP) 结构,特别是n=1,是这些材料中常见的图案.
- 八面体倾斜显著影响矿的对称性和特性.
研究的目的:
- 系统地分析八面体倾斜的可能对称模式在n=1 RP perovskites.
- 将理论预测与实验确定的晶体结构进行比较.
- 了解导致预测对称度偏差的因素.
主要方法:
- 使用对称模式分析来识别所有可能的八面体倾斜模式.
- 分析了140个独特的n=1 RP矿结构的综合数据库.
- 与八面体倾斜相比,研究了结构特征,包括离子包装和层移动.
主要成果:
- 47个不同的对称独特的八面体倾斜模式被确定.
- 88%的分析结构表现出与八面体倾斜预测一致的对称性.
- 偏差归因于有机阴离子包装,八面体扭曲或无机层移动.
- 观察到一种强烈的偏好是相外的φ倾斜 (a/b轴) 与 θ倾斜 (c轴) 结合在一起 (约. 66% 的结构).
- 这些倾斜组合促进了有利的键,以适应不等价的化离子.
结论:
- 对称性分析为了解n=1 RP矿的结构多样性提供了一个强大的框架.
- 八面体倾斜是对称性的主要决定因素,但其他因素可以进一步减少它.
- 特定的倾斜组合,特别是 φ 和 θ 倾斜,由于它们在稳定结构和适应化学变化的作用而受到青.
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