Analytical electron tomography

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation

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Atomic electron tomography in three and four dimensions

MRS Bulletin ◽

10.1557/mrs.2020.88 ◽

2020 ◽

Vol 45 (4) ◽

pp. 290-297 ◽

Cited By ~ 3

Author(s):

Jihan Zhou ◽

Yongsoo Yang ◽

Peter Ercius ◽

Jianwei Miao

Keyword(s):

Electron Tomography ◽

Atomic Electron ◽

Four Dimensions ◽

Image Position

Abstract

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Physical and Practical Challenges in Analytical Electron Tomography of Aluminum Alloys

Microscopy and Microanalysis ◽

10.1017/s1431927615008387 ◽

2015 ◽

Vol 21 (S3) ◽

pp. 1521-1522

Author(s):

A. Orthacker ◽

G. Haberfehlner ◽

J. Tandl ◽

M. C. Poletti ◽

L. J. Allen ◽

...

Keyword(s):

Aluminum Alloys ◽

Electron Tomography ◽

Analytical Electron

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Practical Estimation of Analytical Sensitivity for EDS in an Intermediate Voltage FEG-STEM

Microscopy and Microanalysis ◽

10.1017/s1431927600011715 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 965-966

Author(s):

M. Watanabe ◽

D. W. Ackland ◽

D. B. Williams

Keyword(s):

Spatial Resolution ◽

Single Atom ◽

Acquisition Time ◽

Analytical Sensitivity ◽

X Ray ◽

Quantitative Microanalysis ◽

Analytical Electron ◽

Atom Detection ◽

Electron Microscopes ◽

Image Position

One of the ultimate objectives for energy-dispersive X-ray spectrometry (EDS) in the analytical electron microscope (AEM) is single-atom detection in thin specimens, as well as quantitative microanalysis with high accuracy approaching ±1% relative. In order to realize the single-atom analysis, the design of the AEM has to be optimized with respect to improvements in spatial resolution and detectability limits. The detectability limit, as defined by the minimum mass fraction (MMF), is given by:where P is the peak intensity of interest, (P/B) is the peak-to-background ratio for that peak, and r is the acquisition time. To improve the sensitivity for analysis, any or all of the variables P, (P/B), and τ should be increased. Intermediate-voltage analytical electron microscopes combined with high brightness field-emission gun (FEG) are expected to improve the MMF, while maintaining high spatial resolution. Additionally, the MMF should also be improved by maximizing the solid angle of X-ray collection.

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Statistical Machine Learning and Compressed Sensing Approaches for Analytical Electron Tomography - Application to Phase Change Materials

Microscopy and Microanalysis ◽

10.1017/s143192761900151x ◽

2019 ◽

Vol 25 (S2) ◽

pp. 156-157 ◽

Cited By ~ 1

Author(s):

Martin Jacob ◽

Loubna El Gueddari ◽

Gabriele Navarro ◽

Marie-Claire Cyrille ◽

Pascale Bayle-Guillemaud ◽

...

Keyword(s):

Machine Learning ◽

Compressed Sensing ◽

Phase Change ◽

Phase Change Materials ◽

Electron Tomography ◽

Statistical Machine Learning ◽

Analytical Electron

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A natural example of the disequilibrium breakdown of biotite at high temperature: TEM observations and comparison with experimental kinetic data

Mineralogical Magazine ◽

10.1180/minmag.1987.051.359.09 ◽

1987 ◽

Vol 51 (359) ◽

pp. 93-106 ◽

Cited By ~ 22

Author(s):

A. J. Brearley

Keyword(s):

Kinetic Data ◽

Empirical Method ◽

Reaction Products ◽

Product Phase ◽

Fine Grained ◽

Transmission Electron ◽

Analytical Electron ◽

Analytical Electron Microscope ◽

Image Position ◽

Electron Microscope Data

AbstractTransmission electron microscopy has been used to investigate the mechanism of natural biotite breakdown under pyrometamorphic disequilibrium conditions. Biotite in a xenolith of pelitic gneiss collected from a Tertiary dolerite sill, Isle of Mull, Scotland, shows evidence of an incipient reaction, characterised by a darkening in colour and the appearance of areas of fine-grained reaction products. TEM and analytical electron microscope data show that the reaction can be described as:The orientations of the product phase are controlled by the crystallography of the reacting biotite, demonstrating that the transformation proceeds by a topotactic mechanism. An empirical method, based on the Mg/(Fe2+ + Fe3+) ratios of coexisting spinel and biotite from experimental data, is used to deduce that the reaction occurred above ∼ 770 °C. A comparison of the natural reaction microstructures with those produced experimentally suggest that the xenolith was probably above 800 °C for less than 48 hours and cooled to temperatures of 770 °C after ∼ 150–200 hours.

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Advanced recording schemes for electron tomography

MRS Bulletin ◽

10.1557/mrs.2016.135 ◽

2016 ◽

Vol 41 (07) ◽

pp. 537-541 ◽

Cited By ~ 3

Author(s):

Tim Dahmen ◽

Patrick Trampert ◽

Niels de Jonge ◽

Philipp Slusallek

Keyword(s):

Electron Tomography ◽

Image Position

Abstract

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Maturation of Pseudo-nucleus Compartment in P. aeruginosa, Infected with Giant PhiKZ Phage

10.20944/preprints202008.0633.v1 ◽

2020 ◽

Author(s):

Yana Danilova ◽

Viktoria V. Belousova ◽

Andrey V. Moiseenko ◽

Innokentii E. Vishnyakov ◽

Maria V. Yakunina ◽

...

Keyword(s):

Defense Mechanisms ◽

Electron Tomography ◽

Analytical Electron Microscopy ◽

The Other ◽

Bacterial Dna ◽

Short Intervals ◽

Bacteriophage Infection ◽

Phage Dna ◽

Analytical Electron ◽

Bacterial Cytoplasm

Bacteria develop various defense mechanisms against stresses, including the bacteriophage infection. The giant phiKZ phage infection induced the appearance of a pseudo-nucleus inside the bacterial cytoplasm. Here, we used FISH, electron tomography and analytical electron microscopy to study the morphology of this unique nucleus-like shell and to demonstrate the distribution of phiKZ and bacterial DNA in infected P. aeruginosa cells. The maturation of the pseudo-nucleus was traced in short intervals for 40 min after infection. This study was accompanied by the identification of phiKZ and bacterial DNA by real-time RCR. We demonstrated that phage DNA that isolated from the cytoplasm during all infection stages were compacted within the pseudo-nucleus in a specific structure. Bacterial DNA was diminished in the course of infection, but did not completely degrade until at least 40 min after phage application. The content of the total phage DNA, on the other hand, increased. EDX analysis confirmed these results and revealed that, during the infection, Sulfur content in the bacterial cytoplasm increased, which suggests the increase of DNA-binding Met-reach proteins synthesis, which could protect bacterial DNA from stress.

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