倾斜和扭曲在多铁体奥里维利乌斯阶段Bi6Ti3Fe1.5Mn0.5O18
Louise Colfer1, Núria Bagués2,3, Mohammad Noor-A-Alam1
1Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, Cork T12 R5CP, Ireland.
Chemistry of materials : a publication of the American Chemical Society
|June 17, 2024
概括
比斯木铁氧化物 (B6TFMO) 在室温下表现出多铁的特性. 原子级分析揭示了结构扭曲和电子变异,这些变化对其磁电开关至关重要,从而提高了数据存储潜力.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 纳米技术 纳米技术
背景情况:
- 奥里维利乌斯结构Bi6Ti3Fe1.5Mn0.5O18 (B6TFMO) 是一种罕见的室温多铁材料.
- 它显示了磁场下的铁电领域的可逆磁电切换.
- 对于数据存储应用来说,了解其多铁体行为背后的机制至关重要.
研究的目的:
- 用原子分辨率电子显微镜阐明B6TFMO中八面体倾斜和结构扭曲的相互作用.
- 将这些结构现象与材料的功能性质联系起来.
- 研究复杂的氧化物系统中的电子特征和粘合环境.
主要方法:
- 原子分辨率的电子显微镜.
- 电子能量损失光谱 (EELS) 用于分析电子特征和晶体场分裂.
- 密度函数理论 (DFT) 的计算.
- 原子分辨率的极化向量映射.
- 集成差分相对比 (iDPC) 成像.集成差分相对比 (iDPC) 成像.
主要成果:
- Ti4+电离子电子性质受其在奥里维利乌斯结构中的位置的影响.
- 一层一层的EELS显示了对中心矿层的日益增长的晶体场分裂 (Δ) 趋势 (平均增加0.13±0.06 eV).
- DFT计算和极化映射与四边形扭曲和铁电相关联的Ti4+离子演变.
- iDPC成像显示了向中心层倾斜的升级八面体倾斜,与BO6四边形扭曲相竞争.
- 八面体倾斜,受B位离子排列的影响,是磁性离子并列和铁磁性秩序的关键.
结论:
- 原子层面的结构扭曲和电子变化是B6TFMO多铁体行为的基础.
- 八面体倾斜和四面体扭曲之间的相互作用决定了铁电和铁磁性质.
- 这种详细的理解为设计用于数据存储的先进多铁材料提供了洞察力.
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