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arXiv 0908.0341cond-mat.mtrl-sci
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动力学模拟中旋进电子衍射强度的特征

Characteristics of Precession Electron Diffraction Intensities from Dynamical Simulations

W. Sinkler, L. D. Marks

AI总结:

本文通过多束动力学模拟研究了旋进电子衍射强度的特征,发现旋进能抑制强度随厚度的混沌振荡并降低对结构因子相位的敏感性,同时提出了一种基于散射矩阵非中心列信息的更快速PED强度计算方法。

摘要:

旋进电子衍射(PED)为利用电子衍射进行晶体结构分析和解析未知结构提供了诸多优势。本文结合模型结构,采用多束模拟方法研究PED强度,以更深入地理解PED与标准非旋进电子衍射的差异。研究表明,旋进减弱了电子衍射强度随厚度变化的混沌振荡行为。模拟还揭示了PED的另一个特征:对结构因子相位的敏感性降低。结果表明,这是在多个入射束取向的衍射花样被平均处理的条件下采集的动力学强度所具有的普遍特征。本文还展示了一种新的、显著更快的PED强度动力学计算方法,该方法基于利用散射矩阵非中心列中所包含的信息。

英文摘要:

Precession Electron Diffraction (PED) offers a number of advantages for crystal structure analysis and solving unknown structures using electron diffraction. The current article uses many-beam simulations of PED intensities, in combination with model structures, to arrive at a better understanding of how PED differs from standard unprecessed electron diffraction. It is shown that precession reduces the chaotic oscillatory behavior of electron diffraction intensities as a function of thickness. An additional characteristic of PED which is revealed by simulations is reduced sensitivity to structure factor phases. This is shown to be a general feature of dynami-cal intensities collected under conditions in which patterns with multiple incident beam orienta-tions are averaged together. A new and significantly faster method is demonstrated for dynami-cal calculations of PED intensities, based on using information contained in off-central columns of the scattering matrix.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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