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| We love TEM! (Image is from here) |
Photography is a popular hobby. People take good pictures of nature, showing their beautiful souls to appreciate mother nature. They can take a good picture of their friends, which is an excellent way to make friends happy. In contrast, I, an introvert postdoc, love listen to music, read books, and watch movies. How nerdy I am! Wait! I have a similar jam: photography using electron microscopes. (Damn it! Still, it sounds nerdy.) But I truly love this technique. One of the advantages of today’s inorganic nanocrystal researches is that you can visualize it using electron microscopes. This is the advantage that biochemistry or organic research doesn’t offer at this point. Of course, electron microscopes are getting better and better, e.g., cryo-electron microscopes. We will see what we will see.
That is why electron microscope data can be the core data in your research if you do nanoscience. And, if it is the core data, the quality better is excellent. Here are some tips:
(i) Astigmatism
Check the stigmatism when you do the measurement. During operation, stigmation cannot be avoided, but it is corrected (just like mistakes in life). Check the live FFT and then tune the condenser and objective stigmation.
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| TEM images of nanocrystals (top) and the corresponding FFT patterns (bottom). In the center of the FFT patterns, the white is spherically distributed. Not so good TEM images give oval shapes due to astigmation |
On a TEM sample, dirt can lead to contamination. Try to make pure samples on the TEM grid. Do not cherry-pick, but do not focus on junk, either. TEM only presents highly localized information, so do not be fooled.
(iii) Adjust the brightness and contrast
Adjust the brightness and contrast to show the best pictures. Images provided by the software of the TEM might not be well adjusted; thus, use the brightness and contrast to create the best presentation.
Good luck on your TEM measurement!
