Electron channelling: A method in real-space crystallography and a comparison with the atomic location by channelling-enhanced microanalysis
Electron channelling: A method in real-space crystallography and a comparison with the atomic location by channelling-enhanced microanalysis
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电子沟道：一种实空间晶体学方法以及沟道增强微分析与原子位置的比较
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
W. Sigle
中科院分区：
文献类型：
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作者：
W. Nüchter;W. Sigle
本文描述了一种方法，说明电子沟道如何成功地用于确定晶体中原子的替代格位和间隙格位。这些实验是在配备了X射线探测器的传统透射电子显微镜中进行的。该方法包括槽道剖面的详细测量和这些剖面的计算。拟合程序使我们能够确定特定原子在基本单元中的位置。结果表明，只有在计算中考虑了Bloch波的干扰、非弹性散射电子产生的X射线、内壳层电离事件的离域以及晶体的厚度和形状，才能得到较好的拟合。通过对已知晶体结构(Mo和GaAs)的应用，证明了该方法的适用性。讨论了它与沟道增强微量分析(ALCHEMI)原子位置的关系以及ALCHEMI存在的问题。做个比较。
Abstract A method is described to show how electron channelling can successfully be applied to the determination of substitutional and interstitial lattice sites of atoms in crystals. The experiments are performed in a conventional transmission electron microscope equipped with an X-ray detector. The method includes the detailed measurement of channelling profiles as well as calculations of these profiles. A fitting procedure allows us to determine the location of specific atoms within the elementary cell. It is found that a good fit is obtained only if the interference of Bloch waves, the X-ray production by inelastically scattered electrons, the delocalization of the inner-shell ionization event, and the crystal thickness and shape are considered in the calculation. The applicability of the method is demonstrated by applying it to known crystal structures (Mo and GaAs). Its relation to atomic location by channelling-enhanced microanalysis (ALCHEMI) and the problems of ALCHEMI are discussed. A comparison...