arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2102.12159cond-mat.mtrl-sci
收藏

含30个keV电子的二维材料中原子势的实时成像

Real-time imaging of atomic potentials in 2D materials with 30 keV electrons

Sytze de Graaf, Majid Ahmadi, Ivan Lazić, Eric G. T. Bosch, Bart J. Kooi

摘要:

扫描透射电子显微镜(STEM)是二维(2D)材料原子尺度表征的最广泛采用的工具。许多2D材料仍然易受电子束损伤的影响,尽管标准化实践将束能量从200 keV降低到80或60 keV。尽管所有存在的元素都可以通过使用集成微分相位衬度(iDPC)STEM或电子重叠关联成像的原子静电势成像来检测,但以原子分辨率和增强的灵敏度捕获动态仍然是一个挑战。在这里,通过使用iDPC-STEM,我们通过原子静电势成像捕获二维WS $_2$中的缺陷动力学,其束能量仅为30 keV。具有高帧率的原子静电势的直接成像揭示了WS $_2$中的缺陷和边缘附近的单个原子的存在和运动,否则这些缺陷和边缘用常规的环形暗场STEM是不可见的,或者不能通过电子重叠关联成像足够快地捕获。

英文摘要:

Scanning transmission electron microscopy (STEM) is the most widespread adopted tool for atomic scale characterization of two-dimensional (2D) materials. Many 2D materials remain susceptible to electron beam damage, despite the standardized practice to reduce the beam energy from 200 keV to 80 or 60 keV. Although, all elements present can be detected by atomic electrostatic potential imaging using integrated differential phase contrast (iDPC) STEM or electron ptychography, capturing dynamics with atomic resolution and enhanced sensitivity has remained a challenge. Here, by using iDPC-STEM, we capture defect dynamics in 2D WS$_2$ by atomic electrostatic potential imaging with a beam energy of only 30 keV. The direct imaging of atomic electrostatic potentials with high framerate reveals the presence and motion of single atoms near defects and edges in WS$_2$ that are otherwise invisible with conventional annular dark-field STEM or cannot be captured sufficiently fast by electron ptychography.

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。

↑