Hello,
I have to do some reserach about the preparation of SEM/TEM samples of metal complexes, I can't find anything because they're not usually characterized by microscopic methods.
Any ideas please ?
Dear Mohamed Amine Bourouai , in principle there are no reason a metal complex sample can be analysed by SEM or TEM, unless your samples are sensitive when exposed to air or vacuum, while preparing the sample (in air) or while doing the SEM or TEM images (in vacuum). The electron beam can also cause damages in your samples, depending on the beam energy, exposure times and sample sensitivity. In my experience analysing metal complex, mainly single crystals for X-ray diffraction structure resolution, the samples normally came as crystals in the mother waters where they have grown up. Sometimes, a nice crystal while in the liquid media, becomes a completely cracked one when removed from the original liqueur, sometimes these cracks were not evident under an optical microscope, but once the crystal was ready for measurement the diffraction was clearly of broken crystal (close to powder or with blurry spots). To avoid these problems we used some fluorinated oils to mount and manipulate the crystals, and a flow of cold N2 while recording the data. These measures are not applicable to SEM or TEM, but if your samples are sensitive outside the mother waters, you could use -if available at your university main facilities- some SEM or TEM holders for dealing with liquid samples.
If you are interested just in morphological characterization of your samples, you could check them by means of an optical microscope before and after the SEM/TEM analysis if you are afraid of some damage, change, etc.
Preparation is similar in both cases (SEM and TEM), if your metal complexes are solids and dry, just use a small amount (really tiny) on a SEM stub (sample holder) or a TEM grating (in this case the sample amount must be even smaller and ideally the size of the particles smaller than the grating light (the size of the gratings orifices).
If your sample is dispersed in a solution, just pour a drop of this suspension on the SEM or TEM holder, let it evaporate and then load it into the microscope.
If your samples are dielectrics, a thin coat of conductive layer would be needed for SEM.
Hope this helps. Good luck with your research and best wishes.
Dear Mohamed,
The possible application of SEM/TEM to your samples will depend on several factors:
-How are the samples (solids, suspensions, etc ...)?
-Are they sensitive to radiation?
-Are they stable in high vacuum?
In addition, we will have to see what exactly you want to measure: morphology, atomic structure, electron diffraction???
As you can see, there are many variables and potential uses, but it will all depend on what you want to see and what your samples look like. In principle, unless samples are not stable to electron radiation and high vacuum, they should be capable of being characterized by electron microscopy.
Dear Mohamed,
The possible application of SEM / TEM to your samples will depend on several factors:
-How are the samples (solids, suspensions, etc ...)?
-Are they sensitive to radiation?
-Are they stable in high vacuum?
In addition, we will have to see what exactly you want to measure: morphology, atomic structure, electron diffraction ???
As you can see, there are many variables and potential uses, but it will all depend on what you want to see and what your samples look like. In principle, unless samples are not stable to electron radiation and high vacuum, they should be capable of being characterized by electron microscopy.
Question: what is meant by the term metal complex? Do you mean metal alloys?
Dear Mohamed, with "metal complexes" do you mean metal coordination complexes? Are your samples solid? Are they dissolved in a solvent? What kind of information do you expect from SEM measurements?
Please give additional information so that we can try to help.
Manuel Gómez Dear Manuel I did SEM of suspension of Nano particles which are probably copper oxides but most of them were agglomerated, maybe when putting a droplet one may consider to dilute the suspension and also spin coat it on the silicon or other conductive substrate to avoid aggregation. Sonication may also be helpful.
Regards.
Dear Melika Afshar and all, absolutely! You are right, it could be that the nanoparticle suspension is too concentrated that after evaporation onto the SEM or TEM sample holder, the nanoparticles get aggregated, so it would be indeed a good idea to take an aliquot of your original -concentrated- suspension and dilute it before the evaporation steep. Spincoating can also be very useful because the process spread rapidly the suspension over a large area and that promotes fast evaporation while minimise aggregation.
Thanks for pointing up this important point.
Regards
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