The Difference between TEM and SEM
The Difference between TEM and SEM
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The Difference between TEM and SEM
Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) are instruments use in electron microscopy. The two have differences, various advantage and disadvantages.
SEM uses scattered electrons while TEM uses only transmitted electrons. The SEM’s scattered electrons are known as secondary electrons, while TEM has no classification of electrons. The microscope collects and counts the scattered electrons to produce imaged in SEM. Conversely, in TEM electrons get directly pointed towards the sample and those that go through the sample become part of the illuminated image (Williams, & Carter, 2009). Also, In SEM the focus is made on the surface of the sample and its compositions with TEMS focus goes to the interior of the sample. Furthermore, TEM capture the samples image as a whole but yields two dimensional imaged while SEM capture it in bits by bit and yields a three-dimensional image (Bozzola & Russell, 1999).
TEM, which has a level of magnification of 50 million, has an age over SEM whose magnification is only 2 million maximum. TEM’s resolution is 0.5 angstrom compared to SEM’s resolution of 0.4 nanometers. Regardless, images produced by SEM have a greater depth field than those produced by TEM (Williams, & Carter, 2009).
TEM samples are made thinner while SEM samples are stained by aluminum stubs that capture scattered electrons. It is placed in the instrument chamber at the bottom, and the image is cast on a screen (Bozzola & Russell, 1999). Contrary, TEM sample is papered in a TEM grid and must be positioned at the center of the microscopes chamber. The image is produced through fluorescent screens. Additionally, in SEM the sample can be rotate at different angles.
TEM offer powerful magnification, has a wide range of applications, provides detailed images and is easy to operate. However, it is large and expensive, tedious in the preparation of the sample, requires specific housing and maintenance and provides images in black and white. SEM is also large and expensive. However, it has a wider range of application, high resolution and provides detailed three-dimensional images.
References
Bozzola, J. J., & Russell, L. D. (1999). Electron microscopy: Principles and techniques for biologists. Sudbury, Mass. [u.a.: Jones and Bartlett.
Williams, D. B., & Carter, C. B. (2009). Transmission electron microscopy: A textbook for materials science. New York: Springer.
