Controlling the Spatio-Temporal Dose Distribution During STEM Imaging by Subsampled Acquisition: In-Situ Observations of Kinetic Processes in Liquids



Mehdi, BL ORCID: 0000-0002-8281-9524
(2019) Controlling the Spatio-Temporal Dose Distribution During STEM Imaging by Subsampled Acquisition: In-Situ Observations of Kinetic Processes in Liquids. Applied Physics Letters, 115 (6).

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Abstract

Subsampled image acquisition followed by image inpainting in a scanning transmission electron microscope is a novel approach to control dose and increase the image frame rate during experiments, thereby allowing independent control of the spatial and temporal dose envelope during image acquisition. Here, subsampled imaging is shown to permit precise in situ observations of the fundamental kinetic processes behind nucleation and growth of silver (Ag) nanoparticles from an aqueous solution. At high sampling-levels, nanoparticles can be observed with morphologies that are consistent with strong interface interactions, i.e., rafts and pillars, whereas at low sampling-levels, the particles exhibit regular spherical morphologies. The relative numbers of rafts/pillars and regular nanoparticles, their sizes, and their incubation times can be attributed to local changes in the molar concentration of the Ag ions in the aqueous solution; higher sampling-levels significantly increase the reactants in the vicinity of the window, leading to rapid supersaturation and the precipitation on the window surface. These precisely controlled kinetics highlight subsampled imaging as a method by which the driving force for nucleation and growth (i.e., the electron beam) can be disentangled from the spatial/temporal resolution of the observation in all in situ experiments, providing a pathway to identify and quantify the importance of individual kinetic factors behind nucleation and growth in a wide variety of complex materials systems and architectures. The development of Compressive sensing for EM applications was supported by the Chemical Imaging Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated by Battelle for the U. S. Department of Energy (DOE) under Contract No. DE-AC05-76RL01830. A portion of the research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at PNNL.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 12 Jul 2019 07:21
Last Modified: 20 Oct 2021 21:13
DOI: 10.1063/1.5096595
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3049555