Probing the structure of heterogeneous diluted materials by diffraction tomography
Probing the structure of heterogeneous diluted materials by diffraction tomography
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DOI：
10.1038/nmat2168
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发表时间：
2008-06-01
期刊：
影响因子：
41.2
通讯作者：
Walter, Philippe
中科院分区：
文献类型：
--
作者：
Bleuet, Pierre;Welcomme, Eleonore;Walter, Philippe
纳米科学的出现要求开发局部结构探针，特别是表征无序或异质材料。此外，由于材料的性质往往与其异质性和其结构的层次安排，不同的结构探针覆盖范围广泛的尺度是必需的1 -23。X射线衍射是主要的结构分析方法之一，但检测限相对较差，而透射电子分析涉及破坏性的样品制备。在这里，我们展示了耦合X射线断层扫描与X射线衍射的潜力，以检查纳米材料和多晶材料中的未识别相。该演示是在含有几个碳相（24）的高压球团和含有玉髓和铁颜料的非均匀粉末上进行的。本方法能够实现具有千分之一的重量灵敏度的非侵入性结构细化。它能够提取具有相似原子密度和组成的无定形和结晶化合物的散射图案。此外，这种衍射层析成像实验可以与X射线荧光、康普顿和吸收层析成像同时进行（6），从而实现材料科学、化学、地质学、环境科学、医学、古生物学和文化遗产中最重要的多模态分析。
The advent of nanosciences calls for the development of local structural probes, in particular to characterize ill-ordered or heterogeneous materials. Furthermore, because materials properties are often related to their heterogeneity and the hierarchical arrangement of their structure, different structural probes covering a wide range of scales are required1-23. X-ray diffraction is one of the prime structural methods but suffers from a relatively poor detection limit, whereas transmission electron analysis involves destructive sample preparation. Here we show the potential of coupling pencil-beam tomography with X-ray diffraction to examine unidentified phases in nanomaterials and polycrystalline materials. The demonstration is carried out on a high-pressure pellet containing several carbon phases(24) and on a heterogeneous powder containing chalcedony and iron pigments. The present method enables a non-invasive structural refinement with a weight sensitivity of one part per thousand. It enables the extraction of the scattering patterns of amorphous and crystalline compounds with similar atomic densities and compositions. Furthermore, such a diffraction-tomography experiment can be carried out simultaneously with X-ray fluorescence, Compton and absorption tomographies(6), enabling a multimodal analysis of prime importance in materials science, chemistry, geology, environmental science, medical science, palaeontology and cultural heritage.