I have a particle with core-shell structure, the core contains Ni, Co, Mn oxides while the shell contains Mn oxide. How can I determine the difference between the Mn in the core and the shell? Thanks.
You can do EELS mapped images and see the distribution of the elements with false colours all over the particles. With the same technique, you can choose one element of interest and line-scan it to get the concentration profile accross the particle. It works quite well for core-shell nanoparticles.
Alain
Thank you Sir for your kind reply. Could you please give more details, and how can I do that with digital micrograph?
The treatment is not done on digital micrographs, but the results are directly obtained from the microscope. You select a cross line on your imaged particle, then you ask the microscope to scan the content of the element you want. And you get the profile. It is just like element mapping, but in 1D instead of 2D. Of course, the microscope has to be equipped with the corresponding equipment/option, not all devices (especially older TEM) can do that.
Alain
The coated sample has a particle size around 100 nm, while the uncoated particles with 200 nm.
Moreover, I have 2 diffraction pattern of the coated and uncoated sample. the diffraction pattern of the uncoated sample revels rhombohedral structure with R3m space group. While, the coated material's diffraction pattern revels only one d-space value which is 0.142 nm. what does that mean?
You can also use a EELS-related technique called EFTEM (energy filtered TEM). This is possible with the Gatan imaging filter device and will give you the 2D elemental distribution of selected elements as a 2D intensity map.
What kind of TEM du you have and what kind of equipment is attached to it?
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