What is Electron microscopy: Definition and 16 Discussions

An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects. A scanning transmission electron microscope has achieved better than 50 pm resolution in annular dark-field imaging mode and magnifications of up to about 10,000,000× whereas most light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000×.
Electron microscopes use shaped magnetic fields to form electron optical lens systems that are analogous to the glass lenses of an optical light microscope.
Electron microscopes are used to investigate the ultrastructure of a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. Industrially, electron microscopes are often used for quality control and failure analysis. Modern electron microscopes produce electron micrographs using specialized digital cameras and frame grabbers to capture the images.

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  1. Dario56

    I How Does SEM Compute Sample Structure?

    In SEM, secondary electrons are emitted from the surface of the sample computing surface structure when they reach detector while backscattered electrons give information about structure and chemical composition of internal parts of the sample. However, what I don't understand is what does...
  2. A

    B Electrostatic charge build up in environmental electron microscopy

    Hello, If I understand it correctly, the samples are grounded inside a scanning electron microscope (SEM) to avoid charge build up through the electron beam. Also the non-conductive are coated with a conductive layer, so they can be grounded as well. However, I do not know how the charge build...
  3. mktsgm

    Why not detect and identify SARS-CoV2 using Electron microscopy?

    We know the RT-PCR test method currently employed to detect SARS-CoV2 viruses from the sample is not 100% foolproof in detection. If the current electron microscopy can reach a resolution of up to 50pm, why not use this time-tested technology in the detection of this virus? Are there any...
  4. S

    Transmission electron microscopy -- signal type and importance

    What are the different signals we obtain from TEM and How can we distinguish between them? what are the significances of those signals?
  5. Ferdinand

    Better than electron microscopy?

    I came across your site while looking for information on how to advance our ability to view beyond the capabilities of current electron microscopy technology. I do not know where to start asking but I hoped you could point me in the right direction. I’m about to enroll in university classes and...
  6. A

    Electron speed and acceleration in an electric field

    Hi everyone, I often work on a SEM, a type of microscope which is based on electron acceleration between an electron source and the sample you are working on. For this reason and since a few weeks I was wondering how an electron (in term of speed) behaves in a constant and linear electric field...
  7. B

    Prepare Crystal Sample for SEM Analysis: Ca5(PO4)3OH

    I have a crystal sample that I wish to analyze using scanning electron microscopy (SEM) but is not initially in powder form. What are the proper steps to be taken to prepare the samples for analysis? The substance, I believe, is mainly hydroxylapatite, Ca5(PO4)3OH. Thank you!
  8. G

    B How does electron microscopy exploit wave/particle duality?

    I have been researching wave/particle duality, and I have trouble comprehending how electron microscopy actually exploits wave/particle duality to operate. From Wikipedia, " Wave–particle duality is exploited in electron microscopy, where the small wavelengths associated with the electron can...
  9. Telemachus

    Transmission Electron Microscopy

    I'm looking for a quick and well synthetized reference to the TEM technique. I'm writing a monography, we used TEM on a sample (just sended it to the lab, I dind't do the work). I don't have any reference, and I wanted to give a kind of introduction in the monography to TEM. I don't want a whole...
  10. patrickbotros

    Explain Different Types of Light Microscopy

    Okay so first I would like someone to add detail to my descriptions of different types of light microscopy. Here's what I know: Brightfield (unstained): standard view of partially opaque, live cells. Brightfield (stained): standard view of colored, dead cells. Phase Contrast: Not sure how it...
  11. L

    Which plane of GaN gives an image of dots placed hexagonally

    An electron microscope image of GaN seen in projection shows white dots which correspond to columns of gallium atoms observed in projection. The dots show a hexagonal pattern but there is not a dot in the centre of each hexagonal. No nitrogen atoms are seen in the image. Which plane of this...
  12. I

    A problem about Fresnel fringes of electron microscopy

    My question is simple: Why do the Fresnel fringes at the edge of a hole in a reticulated carbon film become larger and more widely spaced when the defocus is increased? This occurs whether you are over focused or under focused, right? But why?
  13. G

    Advantage of electron microscopy

    What is an advantage of using matter wavelengths over light wavelengths for microscopy? Why to use electron microscopy if one can use X-rays in a range of angstroms. Thank you.
  14. S

    Scanning Electron Microscopy of Graphene

    Hi Everyone, I have recently made some graphene on copper via a chemical vapour deposition process. I have also managed to have a peep under an SEM at this. I do see what I believe to be monolayer graphene. I am very sure the contrast I see is graphene due to the growth patterns, ranging from...
  15. H

    Transmission Electron Microscopy - Crystal Structure

    Hi I have a tutorial problem involving determining the ideal methods for identifying material properties of a layered semiconductor structure. The problem states to use either scanning or transmission electron microscopy. THe structure consists of several monolayers (around 5nm) of AlGaAs...
  16. K

    A Question On Electron Microscopy (TEM)

    Homework Statement Hello! The question is as follows: 1. You are provided with a 1 cm3 of biological sample from which 0.1 mm thin sections are cut. A search for virus cells at a magnification of 100,000 has been proposed. The fluorescent screen on which the image is to be projected...
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