In a TEM image, what causes specific areas of the sample cross-section to appear darker?

Answer

Areas that are denser or absorb a greater number of electrons.

As the electron beam passes through the sample for TEM imaging, regions that are physically denser or absorb more electrons block more beam current, resulting in darker areas on the final image.

In a TEM image, what causes specific areas of the sample cross-section to appear darker?
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