Direct estimation and correction of residual aberrations in the reconstructed exit-wavefunction of a crystalline specimen.
Micron
; 157: 103247, 2022 06.
Article
em En
| MEDLINE
| ID: mdl-35349957
ABSTRACT
Measuring residual aberrations up to second order using a crystalline specimen in transmission electron microscope is challenging. Here, we show by good examples of both experimental and simulated images that it is feasible to measure aberrations up to the second-order, using minimum amplitude contrast criterion for the exit wave function reconstructed. We propose a two-steps strategy for the task (i) Firstly measuring defocus and two-fold astigmatism simultaneously to avoid error accumulation and to reduce the number of dimensions in parameters space. (ii) Then, with minimized misleading effects (or errors) in defocus and two-fold astigmatism, estimations of three-fold astigmatism and coma can be conducted more efficiently and effectively. Influences of other factors such as specimen structure, resolution and specimen thickness on the validity of the method are also discussed in detail. Our study provides a practical procedure for correcting residual aberrations in image wave using crystalline materials, which can then facilitate application of exit wave reconstruction technique to materials research.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Astigmatismo
/
Processamento de Imagem Assistida por Computador
Limite:
Humans
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article