I understand that the count of each element indicated the presence of the element in that particular energy arises from dislocation of electron, but what does the increasing number of keV in EDX spectra for?
Attached is the result of synthesized CaCO3 in carbon dioxide gas. There is no Calcium detected in EDX atomic percentage, but peaks appeared in X-ray diffraction analysis spectra..
Can you show us the SEM-image from where the spectrum was taken?
The x-axis shows the energy emitted when electrons "drop down". For example, when electrons change their level from L to K that would be K-alpha, from M to K K-beta and so on. For Ca, K-alpha is 3.69 keV.
Dear Nurul,
I do not know which kV setting you have used for your spectrum.
For significant yield of the Ca K radiation you want to get, you have to go to for a keV setting of your exciting electron beam, which is welll above the K-edge energy of Ca ( i.e. 4,038keV).
So answering your question: keV setting determines the kinetic energy of your electrons in the beam.
The ionization energies you mention above, are material parameters such as the K- or L-edge energies of the elements. They cannot be changed by the keV setting of your beam.
So please increase your kV setting of well above 4,038kV and you will get your Ca K radiation peaks *) at the energy positions, which are already indicated in your diagram.
Good luck.
*) if Ca is present within the information depth of your set up.
Thomas Fischer Attached is the SEM of where the EDX was taken. what i was trying to do was deposit CaCO3 on FTO substrate. but on FESEM image, only FTO surface was seen, and some EDX gotten the Ca peak but others didnt.
XRD analysis spectra showed presence of CaCO3 crystals though. so im pretty confused whether i managed to deposit the calcium carbonate on FTO substrate or not hence was trying to analyse the atomic composition from the EDX.
Thank you for your answer. I understand better now. That was very helpful of you, i appreciate it.
Thomas Fischer and Gerhard Martens
If you have only partly covered your substrate by CaCo3, you will get an Ca EDX signal only at those points/regions where Ca is present. At other points having no CaCO3 on top of your substrate you will get no Ca EDX signal.This is due to the fact that the exciting electron beam is very limited in its cross section.
However in the XRD case your spatial resolution is very bad; i.e. the net cross-section of the x-ray beam interacts with the whole sample surface. Thus you will get CaCo3 signal even of you have got only some spots of CaCo3 on top of your sample.
Thus your EDX and XRD results are not in contradiction.
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