Dear Dr. Solomon Agbedor,

the main difference between SEM and TEM is that SEM creates an image by detecting reflected or knocked-off electrons while TEM uses transmitted electrons (electrons which are passing through a cutted sample) to create an image. As a result, TEM offers important information on the inner structure of the sample, such as crystal structure, morphology and stress state information, while SEM provides information on the sample’s surface as morphology and chemical composition.

Generally, it's not a bad idea to use two "complementary" techniques to validate the results of a measurement. For example, in relation to the morphology of a surface, SEM measurements (2D) can be compared with measurements obtained using No-contact 3D Optical Profilometry.

Best regards, Pierluigi Traverso.

The requirement of a certain characterization technique strongly depends on the overall purpose of the characterization. Usually, TEM reveals a microstructure/crystallography of extremely limited sample's volume. To obtain an information of significantly larger sample's volumes you need optical and/or scanning electron microscopy. Using SEM, you can also chose a backscattering electrons or secondary electrons detectors to obtain phase or topological images, respectively, or their combination.

Dear Solomon Agbedor,

TEM and SEM will provide you information on order of magnitude different in scale, as the former provide you atomistic/crystal structural wise information while the latter is give more understanding on grain size/porosity type insight.

Regards

Engin

Probably you do not need SEM. What was a purpose of using TEM? Which question was resolved?

It depend on your study purpose.Suppose if you wish to used that catalysis or catalytic activity purse then may be you need to know electron -hole carrier transport path. TEM may be in this case more sensitive . If you characterized the moleular periodicity then you first need to FIB cutting, then HR TEM and of course NMR . Everything depends your purpose of study and your capability.