arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2009.09134cond-mat.mtrl-sciphysics.ins-detphysics.optics
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多束电子衍射

Multibeam Electron Diffraction

Xuhao Hong, Steven E Zeltmann, Benjamin H Savitzky, Luis Rangel DaCosta, Alexander Mueller, Andrew M Minor, Karen Bustillo, Colin Ophus

摘要:

透射电子显微镜(TEM)的主要用途之一是测量衍射图案图像,以确定晶体结构和取向。在纳米束电子衍射(NBED)中,我们在样品上扫描适度会聚的电子探针,以获得数千甚至数百万个连续的衍射图像,这种技术特别适用于多晶样品。然而,由于TEM的大埃瓦尔德球,布拉格峰的激发可能对样品倾斜极其敏感,对于结晶样品,即使是几度的样品倾斜也会强烈变化。在本文中,我们提出了多束电子衍射(MBED),其中多个探针形成孔径用于创建多个STEM探针,所有这些探针同时与样品相互作用。我们详细设计的MBED实验,并使用聚焦离子束(FIB)产生MBED孔径的方法。我们使用模拟和原理验证实验的MBED技术的晶体取向映射的功效。我们还展示了如何使用MBED中的角度信息来执行样本的3D层析重建,而无需多次倾斜或扫描样本。最后,我们还讨论了MBED方法的未来机会。

英文摘要:

One of the primary uses for transmission electron microscopy (TEM) is to measure diffraction pattern images in order to determine a crystal structure and orientation. In nanobeam electron diffraction (NBED) we scan a moderately converged electron probe over the sample to acquire thousands or even millions of sequential diffraction images, a technique that is especially appropriate for polycrystalline samples. However, due to the large Ewald sphere of TEM, excitation of Bragg peaks can be extremely sensitive to sample tilt, varying strongly for even a few degrees of sample tilt for crystalline samples. In this paper, we present multibeam electron diffraction (MBED), where multiple probe forming apertures are used to create mutiple STEM probes, all of which interact with the sample simultaneously. We detail designs for MBED experiments, and a method for using a focused ion beam (FIB) to produce MBED apertures. We show the efficacy of the MBED technique for crystalline orientation mapping using both simulations and proof-of-principle experiments. We also show how the angular information in MBED can be used to perform 3D tomographic reconstruction of samples without needing to tilt or scan the sample multiple times. Finally, we also discuss future opportunities for the MBED method.

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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