TEM operators insist on embedding them in a resin. Will electromagnetic parts of the instrument attract them? My samples are not in powder form. Just a droplet of suspended particles.
I personally operate as sole operator of HRTEM in my university. I observed that it is really a big problem to stabilize the image as magnetic disturbance is always there. To protect the machine from such problem, we use a second carbon coated grid on the grid where you have put the sample- This is the machine part.
However, regarding the sample part, you may follow two different ways to obtain non-hazy images and non-agglomerated samples, for this, you my use a spin coater to drop your sample on the grid, i.e. stick the grid with ithanol on a piece of glass, mount the glass on the spin coater and drop your sample when the glass along with the grid is in spinning condition. collect the grid after it is dried and removable from glass. That will help you to get non agglomerated samples.
for another way , make a very dilute dispersion of your sample, let it rest for some time and collect the solution from the upper part and put that on your TEM grid. That may also help to get non agglomerated separate nanoparticles.
Unfortunately, no trick works for samples like cobalt oxide, i.e. with very high magnetic moments. As per my best knowledge, an attachment is available to filter out the magnetic field of your sample and restrict its interaction with TEM beam. Some JEOL machines have this facility. however, i have not seen any of these machines yet.
There isn't any requirement for the sample preperaton. Just put a droplet of the particles suspension on a copper grid and let it to dry in room temperature. Now it's ready for imaging. You can find this protocol in our and other papers.
Put a droplet of very diluted particles, for example holey grids 300 mesh-Cu, let it dry and ready to go, absolutely no problems to use it. I have done hundreds of times and not problem with any equipment
I personally operate as sole operator of HRTEM in my university. I observed that it is really a big problem to stabilize the image as magnetic disturbance is always there. To protect the machine from such problem, we use a second carbon coated grid on the grid where you have put the sample- This is the machine part.
However, regarding the sample part, you may follow two different ways to obtain non-hazy images and non-agglomerated samples, for this, you my use a spin coater to drop your sample on the grid, i.e. stick the grid with ithanol on a piece of glass, mount the glass on the spin coater and drop your sample when the glass along with the grid is in spinning condition. collect the grid after it is dried and removable from glass. That will help you to get non agglomerated samples.
for another way , make a very dilute dispersion of your sample, let it rest for some time and collect the solution from the upper part and put that on your TEM grid. That may also help to get non agglomerated separate nanoparticles.
Unfortunately, no trick works for samples like cobalt oxide, i.e. with very high magnetic moments. As per my best knowledge, an attachment is available to filter out the magnetic field of your sample and restrict its interaction with TEM beam. Some JEOL machines have this facility. however, i have not seen any of these machines yet.
@Fernando Herranz
Why 300 mesh grids? 150 mesh grids are much bigger openings and are easier to work with.
@Nirmalya Sankar Das
Letting solution to rest for a while will change particle size distribution dramatically. Why would you like to observe non-representative specimen?
@Vladimir Dusevich: Agree with you. But sometime it becomes extremely difficult to obseve the lattice images from agglomerated magnetic samples, for this purpose only my suggested method will be ok. but for size distribution, your point is true- Its not the proper way
Thank you all so much for your input. I'll keep these in mind when working with my TEM operator.
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