Direct observation of local atomic order in a metallic glass
Direct observation of local atomic order in a metallic glass
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DOI：
10.1038/nmat2897
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发表时间：
2011-01-01
期刊：
影响因子：
41.2
通讯作者：
Chen, Mingwei
中科院分区：
文献类型：
--
作者：
Hirata, Akihiko;Guan, Pengfei;Chen, Mingwei
金属玻璃的原子构型的确定是材料科学和固体物理学中长期存在的问题（1,2）。到目前为止，仅从衍射和光谱方法中获得了平均的结构信息。虽然在过去的五十年中提出了各种原子模型（3-8），但对无序材料中局部原子结构的直接观察尚未实现。本文报道用纳米束电子衍射结合从头算分子动力学模拟研究了金属玻璃的局部原子构型。从单个原子团簇和它们的组合中可以观察到不同的衍射模式，这些衍射模式在理论上被预测为中短阶（6-8）。本研究为无序材料的局部原子有序提供了强有力的证据，对理解金属玻璃形成和性质的原子机制具有重要意义。
The determination of the atomic configuration of metallic glasses is a long-standing problem in materials science and solid-state physics(1,2). So far, only average structural information derived from diffraction and spectroscopic methods has been obtained. Although various atomic models have been proposed in the past fifty years(3-8), a direct observation of the local atomic structure in disordered materials has not been achieved. Here we report local atomic configurations of a metallic glass investigated by nanobeam electron diffraction combined with ab initio molecular dynamics simulation. Distinct diffraction patterns from individual atomic clusters and their assemblies, which have been theoretically predicted as short- and medium-range order(6-8), can be experimentally observed. This study provides compelling evidence of the local atomic order in the disordered material and has important implications in understanding the atomic mechanisms of metallic-glass formation and properties.