I have a query about the SEM images; when I analyzed them, they showed some cracks; I stuck to why it can be shown this, what is the reason behind it, and what is the chemistry behind it. I request everyone, please give me an answer as soon as possible; thank you for your attention.
Prakash Yadav Show us the images and tell us about the samples and we’re in a better position to assist.
racked SEM images in material morphology can result from factors like improper sample preparation, drying-induced shrinkage, coating irregularities, inherent material properties (brittleness), and electron beam interactions. Suboptimal mounting, temperature changes, and vacuum conditions can exacerbate cracking. Proper preparation, controlled coating, and optimizing imaging parameters help reduce cracking, ensuring accurate representation of material structures.
Thank you dear sir for your response.
Here is link of SEM image https://photos.app.goo.gl/y7ASDC72he7QtCAd9
and it is a zno nanoparticles sheet, where i observed cracked in sem image
Prakash Yadav I add the image below for convenience. Not all will click on a Google link... The picture shows no evidence of nanoparticles. You state a 'ZnO sheet'. Is this sheet put onto the SEM stub? How did you prepare the specimen for electron microscopy? Was the specimen dry (and thus no free independent, discrete, particles < 100 nm), wet or damp? What was the (conductive) coating and how was it applied? You have many answers in the reply from @Asma Iqbal. Often mismatch between substrate and SEM stub or water removal from the sample can cause this. However, I'd be more worried if you believe that you're displaying a electron micrograph of ZnO nanoparticles...
Asma Iqbal, Thank you for your positive response.
Powders were placed onto the SEM stub after ensuring the samples were thoroughly dried. The preparation of specimens for electron microscopy was carried out by the CRF Centre at IITD. A layer of Au coating was applied to create a conductive surface on the particles. I'm curious about your emphasis on displaying an electron micrograph of ZnO nanoparticles/sheets. Your suggestion could enhance my comprehension of the electron micrograph.
So, what was your specimen? ZnO sheet or powder? In any case it was extremely poorly prepared specimen. Some "protocol" not suitable neither for nanoparticles nor for thin films. Cracks are the least of your problems. By the way, they, cracks, look like cracks in thin organic layer created on specimen surface during drying.
Prakash Yadav
Your response 'Powders were placed onto the SEM stub after ensuring the samples were thoroughly dried' is confusing. I'm trying to figure out whether your difficulties lie in the starting material (is it a suspension, 'comminuted' film, or powder?) itself or the sample preparation for SEM. As others have indicated a drying stage (either prior to or during the evacuation stage in SEM) is likely be responsible. I agree with Vladimir Dusevich that 'Cracks are the least of your problems'. If you had a genuine 'nano' system (100% < 100 nm) and prepared the sample correctly then you should be able to observe separate, discrete, independent particles < 100 nm. At the least you would be showing an aggregation of such particles if this aggregation occurred in the sample preparation stage.
Thank you very much, dear prof Alan F Rawle and Prof Vladimir Dusevich, for providing valuable information about the cracked SEM graph.
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