Entropic Comparison of Atomic-Resolution Electron Tomography of Crystals and Amorphous Materials

Collins, Sean M.; Leary, Rowan K.; Midgley, Paul A.; Tovey, Robert; Benning, Martin; Schönlieb, Carola-Bibiane; Rez, Peter; Treacy, M.M.J.

doi:10.1103/physrevlett.119.166101

“…Therefore, the tilt angles are chosen to be equally spaced, in order to best span the information contained in Fourier space. In contrast to crystalline samples, amorphous materials have no preferred measurement directions and therefore are optimally sampled by equally spaced projections [47]. In order to mimic experimental limitations of many tomography studies, we have also examined the effect of a missing wedge where some range of tilt angles are missing.…”

Section: Microscope and Simulation Parametersmentioning

confidence: 99%

A multiple scattering algorithm for three dimensional phase contrast atomic electron tomography

Ren

¹

,

Ophus

²

,

Chen

³

et al. 2020

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Electron tomography is a technique used in both materials science and structural biology to image features well below optical resolution limit. In this work, we present a new algorithm for reconstructing the three-dimensional(3D) electrostatic potential of a sample at atomic resolution from phase contrast imaging using high-resolution transmission electron microscopy. Our method accounts for dynamical and strong phase scattering, providing more accurate results with much lower electron doses than those current atomic electron tomography experiments. We test our algorithm using simulated images of a synthetic needle geometry dataset composed of an amorphous silicon dioxide shell around a silicon core. Our results show that, for a wide range of experimental parameters, we can accurately determine both atomic positions and species, and also identify vacancies even for light elements such as silicon and disordered materials such as amorphous silicon dioxide and also identify vacancies.

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“…For a reconstruction method we choose to perform a standard total variation reconstruction [51][52][53]:…”

Section: Tomographic Reconstruction Validationmentioning

confidence: 99%

Scanning electron diffraction tomography of strain

Tovey

¹

,

Johnstone

²

,

Collins

³

et al. 2020

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Strain engineering is used to obtain desirable materials properties in a range of modern technologies. Direct nanoscale measurement of the three-dimensional strain tensor field within these materials has however been limited by a lack of suitable experimental techniques and data analysis tools. Scanning electron diffraction has emerged as a powerful tool for obtaining two-dimensional maps of strain components perpendicular to the incident electron beam direction. Extension of this method to recover the full three-dimensional strain tensor field has been restricted though by the absence of a formal framework for tensor tomography using such data. Here, we show that it is possible to reconstruct the full non-symmetric strain tensor field as the solution to an ill-posed tensor tomography inverse problem. We then demonstrate the properties of this tomography problem both analytically and computationally, highlighting why incorporating precession to perform scanning precession electron diffraction may be important. We establish a general framework for non-symmetric tensor tomography and demonstrate computationally its applicability for achieving strain tomography with scanning precession electron diffraction data.

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“…For a reconstruction method we choose to perform a standard Total Variation reconstruction [45][46][47]:…”

Section: Tomographic Reconstruction Validationmentioning

confidence: 99%

Scanning electron diffraction tomography of strain

Tovey,

Johnstone,

Collins

et al. 2020

Preprint

0

View full text Add to dashboard Cite

Strain engineering is used to obtain desirable materials properties in a range of modern technologies. Direct nanoscale measurement of the three-dimensional strain tensor field within these materials has however been limited by a lack of suitable experimental techniques and data analysis tools. Scanning electron diffraction has emerged as a powerful tool for obtaining two-dimensional maps of strain components perpendicular to the incident electron beam direction. Extension of this method to recover the full three-dimensional strain tensor field has been restricted though by the absence of a formal framework for tensor tomography using such data. Here, we show that it is possible to reconstruct the full non-symmetric strain tensor field as the solution to an ill-posed tensor tomography inverse problem. We then demonstrate the properties of this tomography problem both analytically and computationally, highlighting why incorporating precession to perform scanning precession electron diffraction may be important. We establish a general framework for non-symmetric tensor tomography and demonstrate computationally its applicability for achieving strain tomography with scanning precession electron diffraction data.

show abstract

Entropic Comparison of Atomic-Resolution Electron Tomography of Crystals and Amorphous Materials

Cited by 9 publications

References 31 publications

A multiple scattering algorithm for three dimensional phase contrast atomic electron tomography

A multiple scattering algorithm for three dimensional phase contrast atomic electron tomography

Scanning electron diffraction tomography of strain

Scanning electron diffraction tomography of strain

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