Improved high resolution image processing of bright field electron micrographs

Kirkland, Earl J.; Siegel, Benjamin M.; Uyeda, Natsu; Fujiyoshi, Yoshinori

doi:10.1016/0304-3991(85)90002-6

Cited by 81 publications

(54 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The MIMAP method has been successfully demonstrated on an experimental defocus series taken on the Kyoto 500 kV microscope (Kirkland, 1984(Kirkland, , 1988aKirkland et al, 1985). An example application to a calculated defocus series will be shown next.…”

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

“…Allen et al (2004a) used a similar approach with approximate partial coherence and proposed a justification for this approximation (Allen et al, 2004b). An improved method for nonlinear images using accurate partial coherence, called MIMAP, was developed by Kirkland (1984Kirkland ( , 1988a and Kirkland et al (1985). Linear and nonlinear methods have been compared .…”

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

“…This expression can be generalized to include a defocus series of m micrographs as (Kirkland, 1984;Kirkland et al, 1985) pðf…”

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

“…Kirkland (1984) and Kirkland et al (1985) used the obvious approach of successive onedimensional numerical searches in the direction opposite to the gradient [equation (64)], which is called the method of steepest descent. Steepest descent initially produces large improvements but then convergence slows or is nonexistent.…”

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

See 3 more Smart Citations

Computation in electron microscopy

Kirkland

2016

Acta Crystallogr A Found Adv

Self Cite

View full text Add to dashboard Cite

Some uses of the computer and computation in high-resolution transmission electron microscopy are reviewed. The theory of image calculation using Bloch wave and multislice methods with and without aberration correction is reviewed and some applications are discussed. The inverse problem of reconstructing the specimen structure from an experimentally measured electron microscope image is discussed. Some future directions of software development are given.

show abstract

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

“…This expression can be generalized to include a defocus series of m micrographs as (Kirkland, 1984;Kirkland et al, 1985) pðf…”

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

Section: Ctem Exit-wave Reconstructionmentioning

confidence: 99%

See 2 more Smart Citations

Computation in electron microscopy

Kirkland

2016

Acta Crystallogr A Found Adv

Self Cite

View full text Add to dashboard Cite

show abstract

“…These drawbacks relate to the presence of lens aberrations and dynamic diffraction. The development of Cs corrected TEM [1,2] and software that reconstructs the complex electron exit wave function [3][4][5][6][7] aim at removing lens aberrations. Several approaches, such as the 1s state model [8], reversing multislice algorithms [9,10], or simulated annealing and maximum likelihood algorithms [11,12], have been proposed to remove the dynamical scattering effect and to retrieve the crystal potential from the complex exit wave.…”

mentioning

confidence: 99%

Toward Z-Contrast HRTEM by Reversed Multislice Process

Chen

Kisielowski

Jinshek

et al. 2005

MAM

View full text Add to dashboard Cite

In general terms, lattice images do not reveal the real atomic structure of the sample directly, can be distorted, and information about the sample thickness and chemical composition is heavily encoded. These drawbacks relate to the presence of lens aberrations and dynamic diffraction. The development of Cs corrected TEM [1,2] and software that reconstructs the complex electron exit wave function [3][4][5][6][7] aim at removing lens aberrations. Several approaches, such as the 1s state model [8], reversing multislice algorithms [9,10], or simulated annealing and maximum likelihood algorithms [11,12], have been proposed to remove the dynamical scattering effect and to retrieve the crystal potential from the complex exit wave. In this paper, we present a new method to retrieve the potential map from the exit wave based on reversing multi-slice calculations. This algorithm uses a non-linear optimization scheme to find an optimum phase grating that satisfies two boundary conditions: knowledge of the entrance surface wave and the measured exit surface wave. The exit wave of a wedge shaped Au crystal and an Al (10%Cu) crystal were simulated to test this algorithm. Good agreement between the recovered crystal potentials and input parameters was found up to a thickness where phase reversal occurs because of dynamic scattering. After the phase grating is retrieved, the position of atom columns and their chemical composition can be quantified. Compositional maps X a (r) and X b (r) of binary alloys can be deduced from the crystal potential map V(r) using the linear relation V(r) = X a (r)V a +X b (r)V b , where V a and V b are the mean inner potentials of the element A and B, respectively. Figure 1 (a) and (b) show the phase of an electron exit wave of an Al:Cu bi-crystal and an InGaN/GaN quantum well that were reconstructed from focal series of 20 images each. Figure 2 (a) and (b) shows the retrieved potential maps of the Al and Cu atoms, respectively, and sitespecific Cu segregation to the boundary is revealed. Fig. 3 (a) and (b) depicts Ga and In maps from the quantum well region. It is clear from both cases that chemical differences can be distinguished on a single atom level due to the different atomic number Z of the elements. Limitations of the algorithm due to systematic and statistical errors will be discussed.

show abstract

Image processing based on the combination of high-resolution electron microscopy and electron diffraction

1998

Microsc. Res. Tech.

View full text Add to dashboard Cite

A method of crystal structure determination by electron crystallographic image processing based on the combination of high‐resolution electron microscopy (HREM) and electron diffraction is introduced. It consists of two stages: image deconvolution and resolution enhancement. In the first stage an image taken at an arbitrary defocus condition is transformed into the structure image with the resolution depending on the resolution of the electron microscope. In the second stage the image resolution is enhanced to the diffraction resolution limit by combining the electron diffraction data and using the phase extension technique so that in the final image most unoverlapped atoms can be resolved individually. The experimental diffraction intensities are corrected for approximating to square structure factors. The principle of the image processing and the procedure of diffraction intensity correction are briefly described and the results of applications are illustrated. Since the method is based on the weak phase object approximation (WPOA), the validity of WPOA is discussed by introducing an approximate image contrast theory named pseudo weak phase object approximation (PWPOA) to demonstrate the image contrast change with the crystal thickness for very thin crystals. Microsc. Res. Tech. 40:86–100, 1998. © 1998 Wiley‐Liss, Inc.

show abstract

Improved high resolution image processing of bright field electron micrographs

Cited by 81 publications

References 14 publications

Computation in electron microscopy

Computation in electron microscopy

Toward Z-Contrast HRTEM by Reversed Multislice Process

Image processing based on the combination of high-resolution electron microscopy and electron diffraction

Contact Info

Product

Resources

About