scholarly journals What is the Dual-Detector FEG SEM, and Why use it?

1999 ◽  
Vol 7 (1) ◽  
pp. 14-15
Author(s):  
Steve Chapman

The world of scanning electron microscopy seems to spin in such a way that every four years there is a dramatic step forward. Field emission sources (FEG), developed in the late 1960's, started life as a commercial disaster. In spite of the problems, certain manufacturers persisted with the first really user friendly FEG SEM reaching the market in the early 1980s. The FEG has been developed through the 1990's to be, without doubt, the source for SEU. But other advances in SEM performance have added to the instrument's performance, the most recent dramatic step being the introduction of semi-inlens imaging, a technique based upon 1980's dual detector imaging systems.

Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
Enyew Amare Zereffa ◽  
Aschalew Tadesse ◽  
H. C. Ananda Murthy

Abstract Metal oxide nanomaterials are one of the preferences as antibacterial active materials. Due to its distinctive electronic configuration and suitable properties, ZnO is one of the novel antibacterial active materials. Nowadays, researchers are making a serious effort to improve the antibacterial activities of ZnO by forming a composite with the same/different bandgap semiconductor materials and doping of ions. Applying capping agents such as polymers and plant extract that control the morphology and size of the nanomaterials and optimizing different conditions also enhance the antibacterial activity. Forming a nanocomposite and doping reduces the electron/hole recombination, increases the surface area to volume ratio, and also improves the stability towards dissolution and corrosion. The release of antimicrobial ions, electrostatic interaction, reactive oxygen species (ROS) generations are the crucial antibacterial activity mechanism. This review also presents a detailed discussion of the antibacterial activity improvement of ZnO by forming a composite, doping, and optimizing different conditions. The morphological analysis using scanning electron microscopy, field emission-scanning electron microscopy, field-emission transmission electron microscopy, fluorescence microscopy, and confocal microscopy can confirm the antibacterial activity and also supports for developing a satisfactory mechanism. Graphical abstract Graphical abstract showing the metal oxides antibacterial mechanism and the fluorescence and scanning electron microscopic images.


2006 ◽  
Vol 12 (S02) ◽  
pp. 232-233
Author(s):  
A Klaus ◽  
G Hunnicutt

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005


2014 ◽  
Vol 484-485 ◽  
pp. 96-99
Author(s):  
Xue Wen Gao

This paper mainly discusses the Si/Al molar ratio, RO/R2O molar ratio, Fe content, glazing and firing system on the thickness of Longquan Celadon pink coloring effects, and using a colorimeter, field emission scanning electron microscopy were used to analyze better experimental sample microstructure and color and so on. We explored the Longquan Celadon of pink coloration mechanism.


1999 ◽  
Vol 5 (6) ◽  
pp. 413-419 ◽  
Author(s):  
Bernardo R.A. Neves ◽  
Michael E. Salmon ◽  
Phillip E. Russell ◽  
E. Barry Troughton

Abstract: In this work, we show how field emission–scanning electron microscopy (FE-SEM) can be a useful tool for the study of self-assembled monolayer systems. We have carried out a comparative study using FE-SEM and atomic force microscopy (AFM) to assess the morphology and coverage of self-assembled monolayers (SAM) on different substrates. The results show that FE-SEM images present the same qualitative information obtained by AFM images when the SAM is deposited on a smooth substrate (e.g., mica). Further experiments with rough substrates (e.g., Al grains on glass) show that FE-SEM is capable of unambiguously identifying SAMs on any type of substrate, whereas AFM has significant difficulties in identifying SAMs on rough surfaces.


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