A compact parallel‐recording detector for EELS

Egerton, R.F.; Crozier, Peter

doi:10.1111/j.1365-2818.1987.tb02863.x

Cited by 20 publications

(7 citation statements)

References 6 publications

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“…De-* To whom correspondence should be addressed. dicated STEM/EELS instruments have analyzed the chemical analytical potentials of this combination in biological and non-biological materials [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]27]. The formation of elemental distribution images has been described for both combinations [5,8,13,14,17].…”

Section: Introductionmentioning

confidence: 99%

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Quantitative energy-filtered image analysis in cytochemistry

et al. 1990

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A combination of energy-filtered electron microscopy (EFEM) and an image-analyzing system (IBAS/2000) is used for morphometric analyses of cells and (reaction) products. Image contrast is objectively established and segmentation is based upon intrinsic contrasts, in ultrathin sections. Cross-sectioned platinum-stained erythrocytes are used as a model to determine optimal conditions for constant measuring results for contrast, area and perimeter. Results are related to changes in: (1) the objective-lens diaphragm diameter, (2) three most frequently used contrast modes obtainable by electron spectroscopical imaging (ESI) in a Zeiss EM902 transmission electron microscope (e.g., global, zero loss (or AE = 0 eV) and AE = 250 eV), and (3) the number of image integrations (1 -250 × ) acquired by real-time video. A thresholding procedure is proposed for objective segmentation of such contrast-related images and applied to measure the area fraction of nuclear chromatin and the diameter of nominal 1 nm colloidal gold particles.

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Section: Introductionmentioning

confidence: 99%

“…In some STEM instruments, the morphometric accuracy is challenged when small, irregularly shaped, reaction products have to be measured [3][4][5]8,17,27]. The IoI to be imaged has to be covered by an array of multiple points during image and signal acquisition by the use of a digital beam-control system.…”

Section: Introductionmentioning

confidence: 99%

Quantitative energy-filtered image analysis in cytochemistry

et al. 1990

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“…The sample would then yield cross-section ratios which are systematically low. We also note that there may be a containing effect on the oxygen by the carbon contamination since there is some correlation between the OlNi ratio and the carbon signal to background ratio (Egerton et al, 1987;Mansfield et al, 1987). This work illustrates some of the difficulties involved in trying to measure EELS ionization cross-section ratios.…”

Section: T H E O R E T I C a L Cross-section Ratiosmentioning

confidence: 67%

On the determination of inner‐shell cross‐section ratios from NiO using EELS

Crozier

Chapman

Craven

et al. 1987

Journal of Microscopy

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We have attempted to measure the O/Ni inner-shell cross-section ratios from a sample of NiO using EELS in an electron microscope. The results lay within roughly 10% of the predictions of both the hydrogenic and Hartree-Slater theories. However, the data showed a spread of around 20% which may have been caused by artefacts introduced during the specimen preparation. I N T R O D U C T I O NElectron energy loss spectroscopy (EELS) is a technique which can be employed in electron microscopy for determining the elemental concentration ratios in small volumes within a sample. The most commonly used procedure for quantifying the energy-loss spectrum involves recourse to theoretical inner-shell atomic cross sections and there have been few attempts to determine concentration ratios using purely empirical procedures (Grande & Ahn, 1983;Malis & Titchmarsh, 1985). Such procedures have been applied for many years in X-ray analysis and include, for example, the k-factor method proposed by Cliff & Lorimer (1975). The relevant k-factors in EELS differ from those used in EDX in that they are a function of the energy integration range, the collection angle and the specimen thickness. In addition, the near-edge structure of the core-loss signal depends on the chemical environment of the atomic species of interest which, together with the previously mentioned factors, complicates the implementation of the k-factor approach as a routine method of analysis in EELS. However, in very thin samples, where the scattering parameter (the ratio of specimen thickness to inelastic mean free path) is less than 0.5, the EELS k-factor is simvly the ratio of the inner-shell vartial ionization cross sections for the A -two elements involved, provided the energy integration region is large enough to make fine structure effects negligible (Egerton, 1981a). Thus, a k-factor approach can be used to provide information on the accuracy of the predictions of theoretical atomic models.The main problem with the k-factor method lies in the need to find suitable standards of accurately known composition. We have carried out measurements on single-crystal NiO using a VG HB5 STEM equipped with post-specimen lenses (Craven & Buggy, 1981) and

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“…These sensors have shown great potential for in situ microscopy 19 , 20 and have revolutionized low-dose analysis, lifting single-particle cryo-TEM to the Nature Methods 2015 Method of the Year 21 – 25 . Application of this new generation of DD sensors to electron spectroscopy 26 , 27 may yield similarly exciting results.…”

Section: Introductionmentioning

confidence: 98%

Direct Detection Electron Energy-Loss Spectroscopy: A Method to Push the Limits of Resolution and Sensitivity

Hart

Lang

Leff

et al. 2017

Sci Rep

125

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In many cases, electron counting with direct detection sensors offers improved resolution, lower noise, and higher pixel density compared to conventional, indirect detection sensors for electron microscopy applications. Direct detection technology has previously been utilized, with great success, for imaging and diffraction, but potential advantages for spectroscopy remain unexplored. Here we compare the performance of a direct detection sensor operated in counting mode and an indirect detection sensor (scintillator/fiber-optic/CCD) for electron energy-loss spectroscopy. Clear improvements in measured detective quantum efficiency and combined energy resolution/energy field-of-view are offered by counting mode direct detection, showing promise for efficient spectrum imaging, low-dose mapping of beam-sensitive specimens, trace element analysis, and time-resolved spectroscopy. Despite the limited counting rate imposed by the readout electronics, we show that both core-loss and low-loss spectral acquisition are practical. These developments will benefit biologists, chemists, physicists, and materials scientists alike.

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A compact parallel‐recording detector for EELS

Cited by 20 publications

References 6 publications

Quantitative energy-filtered image analysis in cytochemistry

Quantitative energy-filtered image analysis in cytochemistry

On the determination of inner‐shell cross‐section ratios from NiO using EELS

Direct Detection Electron Energy-Loss Spectroscopy: A Method to Push the Limits of Resolution and Sensitivity

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