Thick specimens in the CEM and STEM. I. Contrast

Crewe, A. V.; Groves, Timothy R.

doi:10.1063/1.1663833

Cited by 52 publications

(14 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Crewe and Groves have described the considerations that must be made to calculate the image intensities for thick specimens and explicitly calculated the thickness contrast from carbonaceous specimens with and without energy filtration [33]. We have used a similar approach to calculate the density contrast from biological molecules embedded in thick layers of ice.…”

Section: Multiple Scatteringmentioning

confidence: 99%

Quantitative energy-filtered electron microscopy of biological molecules in ice

1992

View full text Add to dashboard Cite

The theoretical and experimental bases for quantitative electron microscopy of frozen-hydrated specimens are described, with special considerations of energy filtration to improve the images. The elastic and inelastic scattering from molecules in vacuum and in ice are calculated, and simple methods to approximate scattering are introduced. Multiple scattering calculations are used to describe the scattering from vitreous ice and to predict the characteristics of images of frozen-hydrated molecules as a function of ice thickness and accelerating voltage. Energy filtration is predicted to improve image contrast and signal-to-noise ratio. Experimental values for the inelastic scattering of ice, the energy spectrum of thick ice, and the contrast of biological specimens are determined. The principles of compensation for the contrast transfer function are presented. Tobacco mosaic virus is used to quantify the accuracy of interpreting image intensities to derive the absolute mass, mass per unit length, and internal mass densities of biological molecules. It is shown that compensation for the contrast transfer function is necessary and sufficient to convert the images into accurate representations of molecular density. At a resolution of 2 nm, the radial density reconstructions of tobacco mosaic virus are in quantitative agreement with the atomic model derived from X-ray results.

show abstract

Section: Multiple Scatteringmentioning

confidence: 99%

Quantitative energy-filtered electron microscopy of biological molecules in ice

1992

View full text Add to dashboard Cite

show abstract

“…6 Some of the nanoscale devices, however, are fabricated on a thick substrate ͑Ͼ100 m͒ which does not allow the electron beam to penetrate the device. High-resolution imaging methods such as scanning electron microscopy ͑SEM͒, transmission electron microscopy ͑TEM͒, and scanning transmission electron microscopy ͑STEM͒ have provided direct evidence of nanoscale phenomena using recently developed in situ imaging techniques.…”

Section: Introductionmentioning

confidence: 99%

Bright-field transmission imaging of carbon nanofibers on bulk substrate using conventional scanning electron microscopy

Suzuki¹,

Ngo²,

Kitsuki³

et al. 2007

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

Monte Carlo simulation of scanning electron microscopy bright contrast images of suspended carbon nanofibers Appl. Phys. Lett. 90, 083111 (2007); 10.1063/1.2450655Bright contrast imaging of carbon nanofiber-substrate interface Electron field emission from room temperature grown carbon nanofibersThe authors present scanning transmission electron microscopy ͑STEM͒ of carbon nanofibers ͑CNFs͒ on a bulk substrate using conventional scanning electron microscopy ͑SEM͒ without specimen thinning. By utilizing the electron beam tilted Ͼ85°from the substrate normal, bright-field STEM contrast is obtained for the CNFs on substrate with conventional SEM. Analysis of the observed contrast using Monte Carlo simulation shows that the weakly scattered electrons transmitted from the CNF are selectively enhanced by the largely tilted substrate and result in the observed STEM contrast. This mechanism provides a useful STEM imaging technique to investigate the internal structure of materials on bulk substrates without destructive specimen thinning.

show abstract

“…There have been numerous useful mass measurements of thin specimens (e.g. Engel, 1978;Lamvik, 1978;Reedy et al, 1981;Wall et al, 1983) but few of the mass distribution within thick structures (Crewe & Groves, 1974), where demands on the signal-tonoise ratio of the original image are greater. Concentration determinations by microanalysis of volatile elements or of elements in unstable matrices will be improved with reduced mass loss.…”

Section: Discussionmentioning

confidence: 99%

Mass loss rate in collodion is greatly reduced at liquid helium temperature

Lamvik

Kopf

Davilla

1987

Journal of Microscopy

View full text Add to dashboard Cite

Collodion, mass loss, radiation damage, superconducting lens, electron energy loss spectrometer, inelastic electron scattering, low temperature electron microscopy, analytical electron microscopy. S U M M A R YThe mass thickness of collodion films has been monitored at several temperatures, under conditions typical of electron microscopy, through the use of an electron energy loss spectrometer. Compared to room temperature, only a five-fold reduction in the rate of mass loss was observed through the use of a commercial liquid nitrogen cooled stage; in contrast, the rate of mass loss was reduced more than one hundred fold when these films were held at liquid helium temperature.

show abstract

Thick specimens in the CEM and STEM. I. Contrast

Cited by 52 publications

References 6 publications

Quantitative energy-filtered electron microscopy of biological molecules in ice

Quantitative energy-filtered electron microscopy of biological molecules in ice

Bright-field transmission imaging of carbon nanofibers on bulk substrate using conventional scanning electron microscopy

Mass loss rate in collodion is greatly reduced at liquid helium temperature

Contact Info

Product

Resources

About