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arXiv 1903.04780cond-mat.mtrl-sci
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一种用于原子分辨率成像的基于Doppler的机制

A symmetry-derived mechanism for atomic resolution imaging

Matus Krajnak, Joanne Etheridge

摘要:

我们介绍了一种新的扫描透射电子显微镜(STEM)的图像对比度机制,来自局部对称性内的标本。对于样品上的电子探针的给定位置,图像强度由出射电子强度分布和应用于该分布的所选对称操作之间的相似程度来确定。对比机制检测轻和重的原子柱,是强大的样品厚度,电子探针能量和散焦方面。原子柱表现为尖锐的峰,其可以比使用常规圆盘和环形检测器的STEM图像明显更窄。这种根本不同的对比机制补充了传统的成像模式,并可以与它们同时采集,扩展了STEM用于材料表征的能力。

英文摘要:

We introduce a new image contrast mechanism for scanning transmission electron microscopy (STEM) that derives from the local symmetry within the specimen. For a given position of the electron probe on the specimen, the image intensity is determined by the degree of similarity between the exit electron intensity distribution and a chosen symmetry operation applied to that distribution. The contrast mechanism detects both light and heavy atomic columns and is robust with respect to specimen thickness, electron probe energy and defocus. Atomic columns appear as sharp peaks that can be significantly narrower than for STEM images using conventional disc and annular detectors. This fundamentally different contrast mechanism complements conventional imaging modes and can be acquired simultaneously with them, expanding the power of STEM for materials characterisation.

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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