Determination of Atomic Positions from Time Resolved High Resolution Transmission Electron Microscopy Images
Zahra Hussaini, Pin A. Lin, Bharath N. Natarajan, Wenhui Zhu, Renu Sharma
For a large number of reaction processes such as catalysis, phase transformation, nanomaterial synthesis etc., nanoscale observations at high spatial (atomic scale) and temporal (time) resolution are required to understand and measure the underlying favorable factors. Recent developments in image acquisition systems for transmission electron microscopes enabled recording atomic resolution images of chemical and structural transformations as a result of external stimuli at a temporal resolution ranging from 0.16 s to 0.0006 s.1,2 Video recordings of these changes are rich with information if structural (and thereby chemical) information can be deciphered from each frame. Fast Fourier Transforms of a selected area of the atomic resolution images has been successfully used for structure identification.3 However, this method is applicable only if the structure of the entire nanoparticle changes with time and is limited to nanoparticle size of more than 5 nm.3 Here we present a methodology for automated quantitative measurement of atomic position fluctuations in different parts of the same nanoparticle. We leverage on several image processing algorithms to identify the positions of the atomic columns in each image. A geometric model is then used to quantify the distances and angles between neighboring atomic columns over time to measure the local structural fluctuations. We apply this technique to quantify the number of carbon atoms incorporated and released in catalyst nanoparticles during the growth of single walled carbon nanotube. These atomic level fluctuations between metal and carbide phase were then used to resolve carbon pathways in these catalyst nanoparticles for the growth. We show that the method is universally applicable to measure atomic positions with a precision of 0.01 nm from any set of high resolution video images and anticipate it will be crucial in addressing the me
, Lin, P.
, Natarajan, B.
, Zhu, W.
and Sharma, R.
Determination of Atomic Positions from Time Resolved High Resolution Transmission Electron Microscopy Images, Ultramicroscopy, [online], https://doi.org/10.1016/j.ultramic.2017.12.018, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923773
(Accessed December 3, 2023)