Mawson T, Taplin D J, Brown H G, Clark L, Ishikawa R, Seki T, Ikuhara Y, Shibata N, Paganin D M, Morgan M J, Weyland M, Petersen T C, Findlay S D
School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
Ian Holmes Imaging Center, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia.
Ultramicroscopy. 2022 Mar;233:113457. doi: 10.1016/j.ultramic.2021.113457. Epub 2021 Dec 31.
Quantitative differential phase contrast imaging of materials in atomic-resolution scanning transmission electron microscopy using segmented detectors is limited by various factors, including coherent and incoherent aberrations, detector positioning and uniformity, and scan-distortion. By comparing experimental case studies of monolayer and few-layer graphene with image simulations, we explore which parameters require the most precise characterisation for reliable and quantitative interpretation of the reconstructed phases. Coherent and incoherent lens aberrations are found to have the most significant impact. For images over a large field of view, the impact of noise and non-periodic boundary conditions are appreciable, but in this case study have less of an impact than artefacts introduced by beam deflections coupling to beam scanning (imperfect tilt-shift purity).
在原子分辨率扫描透射电子显微镜中使用分段探测器进行材料的定量微分相衬成像受到多种因素的限制，包括相干和非相干像差、探测器定位与均匀性以及扫描畸变。通过将单层和少层石墨烯的实验案例研究与图像模拟进行比较，我们探究了哪些参数对于可靠且定量地解释重建相位需要最精确的表征。结果发现相干和非相干透镜像差的影响最为显著。对于大视场图像，噪声和非周期性边界条件的影响较为明显，但在本案例研究中，其影响小于由光束偏转与光束扫描耦合（不完美的倾斜-位移纯度）引入的伪像。
