Optimization of STEM-HAADF electron tomography reconstructions by parameter selection in compressed sensing total variation minimization-based algorithms
Abstract
A novel procedure to optimize the 3D morphological characterization of nanomaterials by means of high angle annular dark field scanning‐transmission electron tomography is reported and is successfully applied to the analysis of a metal‐ and halogen‐free ordered mesoporous carbon material. The new method is based on a selection of the two parameters (μ and β) which are key in the reconstruction of tomographic series by means of total variation minimization (TVM). The parameter‐selected TVM reconstructions obtained using this approach clearly reveal the porous structure of the carbon‐based material as consisting of a network of parallel, straight channels of ≈6 nm diameter ordered in a honeycomb‐type arrangement. Such an unusual structure cannot be retrieved from a TVM 3D reconstruction using default reconstruction values. Moreover, segmentation and further quantification of the optimized 3D tomographic reconstruction provide values for different textural parameters, such as pore size distribution and specific pore volume that match very closely with those determined by macroscopic physisorption techniques. The approach developed can be extended to other reconstruction models in which the final result is influenced by parameter choice.
Citation
Muñoz-Ocaña , J M , Bouziane , A , Sakina , F , Baker , R T , Hungría , A B , Calvino , J J , Rodríguez-Chía , A M & López-Haro , M 2020 , ' Optimization of STEM-HAADF electron tomography reconstructions by parameter selection in compressed sensing total variation minimization-based algorithms ' , Particle & Particle Systems Characterization , vol. 37 , no. 6 , 2000070 . https://doi.org/10.1002/ppsc.202000070
Publication
Particle & Particle Systems Characterization
Status
Peer reviewed
ISSN
0934-0866Type
Journal article
Description
This work has received financial support from FEDER/MINECO (MAT2017‐87579‐R, MAT2016‐81118‐P, and MTM2016‐74983‐C2‐2‐R). NetmeetData Project from Fundación BBVA convocatoria 2020. Junta de Andalucía is also acknowledged (MULTITOM Project, P18‐FR‐1422 Project FQM334, FQM355). J.M.M. acknowledges the Youth Employment Program (Plan de Empleo Juvenil) of Junta de Andalucía. Electron microscopy data were acquired using the equipment at the DME‐UCA node of the ELECMI Spanish Unique Infrastructure for Electron Microscopy of Materials. The authors thank the University of St. Andrews for a Ph.D. scholarship for F.S.Collections
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