The Effect of Dynamical Scattering on Single-plane Phase Retrieval in Electron Ptychography

TY - JOUR

T1 - The Effect of Dynamical Scattering on Single-plane Phase Retrieval in Electron Ptychography

AU - Clark, Laura

AU - Martinez, Gerardo T.

AU - O’Leary, Colum M.

AU - Yang, Hao

AU - Ding, Zhiyuan

AU - Petersen, Timothy C.

AU - Findlay, Scott D.

AU - Nellist, Peter D.

N1 - Funding Information: This research was partly supported under the Discovery Projects funding scheme of the Australian Research Council (Project No. DP160102338). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 891504. Support is gratefully acknowledged from the EPSRC (EP/K040375/1 “South of England Analytical Electron Microscope”), the Henry Royce Institute for Advanced Materials (EP/R00661X/1, EP/S019367/1, and EP/R010145/1) and grant number EP/M010708/1. Financial support was also received from the EU H2020 Grant No. 823717 ESTEEM3. Publisher Copyright: © The Author(s) 2022.

PY - 2023/2/1

Y1 - 2023/2/1

N2 - Segmented and pixelated detectors on scanning transmission electron microscopes enable the complex specimen transmission function to be reconstructed. Imaging the transmission function is key to interpreting the electric and magnetic properties of the specimen, and as such four-dimensional scanning transmission electron microscopy (4D-STEM) imaging techniques are crucial for our understanding of functional materials. Many of the algorithms used in the reconstruction of the transmission function rely on the multiplicative approximation and the (weak) phase object approximation, which are not valid for many materials, particularly at high resolution. Herein, we study the breakdown of simple phase imaging in thicker samples. We demonstrate the behavior of integrated center of mass imaging, single-side band ptychography, and Wigner distribution deconvolution over a thickness series of simulated GaN 4D-STEM datasets. We further give guidance as to the optimal focal conditions for obtaining a more interpretable dataset using these algorithms.

AB - Segmented and pixelated detectors on scanning transmission electron microscopes enable the complex specimen transmission function to be reconstructed. Imaging the transmission function is key to interpreting the electric and magnetic properties of the specimen, and as such four-dimensional scanning transmission electron microscopy (4D-STEM) imaging techniques are crucial for our understanding of functional materials. Many of the algorithms used in the reconstruction of the transmission function rely on the multiplicative approximation and the (weak) phase object approximation, which are not valid for many materials, particularly at high resolution. Herein, we study the breakdown of simple phase imaging in thicker samples. We demonstrate the behavior of integrated center of mass imaging, single-side band ptychography, and Wigner distribution deconvolution over a thickness series of simulated GaN 4D-STEM datasets. We further give guidance as to the optimal focal conditions for obtaining a more interpretable dataset using these algorithms.

KW - 4D-STEM

KW - phase retrieval

KW - ptychography

KW - scanning transmission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=85153331724&partnerID=8YFLogxK

U2 - 10.1093/micmic/ozac022

DO - 10.1093/micmic/ozac022

M3 - Article

AN - SCOPUS:85153331724

SN - 1431-9276

VL - 29

SP - 384

EP - 394

JO - Microscopy and Microanalysis

JF - Microscopy and Microanalysis

IS - 1

ER -