Probe integrated scattering cross sections in the analysis of atomic resolution HAADF STEM images
Probe integrated scattering cross sections in the analysis of atomic resolution HAADF STEM images
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DOI：
10.1016/j.ultramic.2013.07.002
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发表时间：
2013-10-01
期刊：
影响因子：
2.2
通讯作者：
Nellist, P. D.
中科院分区：
文献类型：
--
作者：
E, H.;MacArthur, K. E.;Nellist, P. D.
使用探针位置积分截面（PICS）作为一种有效的方式来比较模拟和实验在高角度环形暗场（HAADF）扫描透射电子显微镜（STEM）的单柱原子的物理基础进行了描述，并使用PICS，以使图像强度的定量使用进行评估。它基于检测器的校准和散射强度的测量。由于HAADF STEM的主要不相干性质，它被发现是鲁棒的参数，影响探头的大小和形状，如散焦和源相干。主要成像参数依赖于探测器角度和加速电压，这是众所周知的。对其他参数变化的鲁棒性允许实验数据和模拟的定量比较，而不需要点亮参数。通过演示[PICS]在非均相催化剂和薄层状材料中对单个原子的化学鉴定的应用，我们探索了使用这种方法时的一些实验考虑。(C)2013爱思唯尔有限公司版权所有。
The physical basis for using a probe-position integrated cross section (PICS) for a single column of atoms as an effective way to compare simulation and experiment in high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) is described, and the use of PICS in order to make quantitative use of image intensities is evaluated. It is based upon the calibration of the detector and the measurement of scattered intensities. Due to the predominantly incoherent nature of HAADF STEM, it is found to be robust to parameters that affect probe size and shape such as defocus and source coherence. The main imaging parameter dependencies are on detector angle and accelerating voltage, which are well known. The robustness to variation in other parameters allows for a quantitative comparison of experimental data and simulation without the need to lit parameters. By demonstrating the application of the [PICS to the chemical identification of single atoms in a heterogeneous catalyst and in thin, layered-materials, we explore some of the experimental considerations when using this approach. (C) 2013 Elsevier B.V. All rights reserved.