Is it possible to eliminate surface charging of a insulator or polymer sample without conductive coating?
Is your polymer in contact with another surface? If so, check where the two materials are on the triboelectric series. If they are far removed charging will occur.
Yes, if you work under certain chamber pressure, e.g. e few Pascal nitrogen or air. These SEMs are commonly called "low vacuum" or "variable pressure" instruments.
Another possibility is to use particles with positive charge for imaging and an electron flood gun for charge compensation. A Helium Ion Microscope is capable of such an operation, but it is also quite expensive..
Thus, low vac operation, like Gert Nolze mentioned, is the easiest way. The residual gas inside the chamber (at comparable high pressure) can be used to discharge the sample surface.
A third solution which I heard of, but never tried, is to find the point of accelerating voltage where your secondary electron yield is equal to the absorbed beam current. In this way, you gain a net current of zero and should get less charging.
Apologies for my answer, I didnt realize this was a question about SEM imaging. Gert and Bjorn definitely make good/interesting suggestions
Well, now that you say it, there is no direct evidence that Abbas Rahdar meant charging during SEM imaging.. Maybe a clarification of the question would be good!
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