离子空缺诱导的磁性晶体异质性在化六角合金中
Olivier Mentré1, Houria Kabbour, Ghislaine Ehora
1Unité de Catalyse et de Chimie du Solide, CNRS UMR 8181, ENSC Lille - UST Lille, BP 90108, 59652 Villeneuve d'Ascq cedex, France.
Journal of the American Chemical Society
|March 16, 2010
概括
合成和表征了两个新的六角矿. 空缺影响离子的自旋状态和方向,影响材料特性.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 基于的六角矿石因其磁性和电子性质而受到关注.
- 了解结构,电子配置和磁性行为之间的关系对于材料设计至关重要.
研究的目的:
- 为了合成和描述两个新的六角矿: 6H-Ba(6) Co(6) F(0.93) O(16) 和10H-Ba(5) Co(5) F(0.77) O(12.88).
- 调查空缺对这些材料电子结构和磁性特性的影响.
主要方法:
- 用X射线和中子衍射进行结构分析.
- (19)F 固态核磁共振 (NMR) 光谱. 固态核磁共振 (NMR) 光谱.
- 测量磁性易感性和电电阻力.
- 密度函数理论 (DFT) 和电子结构的紧密结合计算.
主要成果:
- 确定了这两种矿的晶体结构,揭示了共享角的四面体Co(2) O(7) 模和共享面的八面体寡合体.
- 建立了一个电荷分布模型,将高旋转的Co3+) 分配给四面体位,而低旋转的Co3+) /Co4+) 分配给八面体位.
- 在[BaOF(1-x) 层中的空缺导致四面体二面体的显著扭曲,改变了Co(3+) 离子的旋转方向.
结论:
- 该研究阐明了空缺在调节六角矿中离子旋转方向方面的关键作用.
- 这些发现为电子结构和磁性特性提供了洞察力,为设计相关的氧化和氧化提供了基础.
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