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Fabrication of Spatially Confined Complex Oxides
Published on: July 1, 2013
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在高氧化物中探测局部位置障碍和扭曲
Bo Jiang, Craig A Bridges, Raymond R Unocic
1Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
Journal of the American Chemical Society
|December 22, 2020
概括
高氧化物 (HEO) 提供可调节的功能. 这项研究揭示了火高温体中M位子的变化如何控制局部秩序,从而影响先进设计的材料特性.
科学领域:
- 材料科学
- 固态化学
- 晶体学
背景情况:
- 高氧化物 (HEO) 是由于其复杂的组成而具有调节性质的材料.
- 控制当地的原子秩序和混乱对于释放HEO的全部潜力至关重要.
- 具有多个M位点的Pyrochlore HEOs为研究局部结构-属性关系提供了一个独特的平台.
研究的目的:
- 合成和描述具有五个M位子阳离子 (Nd2M2O7) 的新型高化物.
- 使用先进的实验和计算技术研究M位点的局部秩序/混乱.
- 通过了解当地的原子安排如何影响材料的行为来建立结构属性相关性.
主要方法:
- 中子衍射和对分布函数 (PDF) 分析以探测局部原子结构.
- 用特殊的准随机结构 (SQS) 模型进行密度函数理论 (DFT) 计算,以计算理论PDF.
- 反向蒙特卡罗 (RMC),初始分子动力学 (AIMD) 和大都会蒙特卡罗 (MMC) 模拟来分析M位点的秩序/混乱.
主要成果:
- 合成的火的平均结构是形的.
- Nd2(Ta0.2Sc0.2Sn0.2Hf0.2Zr0.2) 2O7在局部到纳米尺度上表现出高度随机/无序的M位子.
- Nd2(Ti0.2Nb0.2Sn0.2Hf0.2Zr0.2) 2O7+在亚纳米尺度上显示了显著的TiO6八面体扭曲和Ti的短距离顺序 (SRO),可能是内在的.
结论:
- 在HEO中M位离子的工程变化,即使有相似的半径,也可以精确地控制局部秩序/混乱的动机.
- 了解和控制局部原子安排是为特定应用量身定制HEO属性的关键.
- 先进的计算和实验分析对于指导高等教育机构的结构属性调整至关重要.
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