I was researching about CuMOF and was confused by the SEM EDX test results. Is it true that coating with gold in the SEM test makes the EDX results unable to show element C (atomic weight C in my research is 0%). And there are other elements such as Al, Si, S, K, Cr, and Fe that can be read, why is it like this?
Au coating is not recommended for EDS, use some nm of carbon instead if needed. Maybe you could show an EDS spectrum.
there are many times researcher facing same problem in EDS results. so i suggest you to please go with XPS.
EDX analyses the characteristic X-rays coming from the sample surface. In samples coated with gold, gold peaks may appear in the spectrum, since the characteristic X-rays of the gold itself will also be detected. This can complicate the spectral analysis of the sample material and lead to incorrect results. If the coating is too thick, it can weaken the signals from the sample material underneath and the signals from the coating alone may dominate. This prevents the sample from being analysed correctly. Alternatively, other coating materials such as carbon can be used to overcome the problem of insulating properties, since carbon has a lesser effect on the EDX spectrum than gold.
You have two good answers there. (Devarshi's comment comment about XPS is less helpful. It only analyzes the surface, i.e., top layer; contamination can be a real problem. Also, it had MUCH less spatial resolution.)
It would help to see a spectrum to know more details. Au will definitely introduce extra peaks. I have encountered samples where the gold thickness was extreme and it both kept the beam from reaching the sample and it absorbed many of the x-rays that were generated.
In addition, the Au-N line overlaps the C-K line. That renders analysis problematic. Again, if you can provide some details about the particular EDS system, we can help more. I have used several different systems and they take different approaches to quantification.
What do you hope to learn from the C analysis? I suggest you limit yourself to qualitative information. It is very difficult, if not impossible, to analyze C well.
Your sample with gold for SEM (Scanning Electron Microscopy) can indeed affect the EDX (Energy Dispersive X-ray Spectroscopy) results. Gold coating is commonly used to improve the conductivity of the sample and enhance image quality, but it can interfere with the detection of certain elements and overshadows with light atom such as carbon.On countrary the metals signals can be easily distinguished from the background noise in case of Al ,Si Cr etc.even in presence of gold plating. Instead of gold plating carbon plating would be better alternative.
Prithvi Rasaili, I advise against the use of the term "plating". A conductive "coating" is applied by evaporation or sputtering.
It is important to keep the thickness as thin as possible while achieving conductivity. We used to apply 15 nm of gold, but we now use less than 5 nm iridium. It is more expensive but yields a much better coating with less effect on the spectrum.
C is good for EDS, as you mentioned. However, it does not yield as good a SE signal as a gold or iridium coating.
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