Hi dear colleagues! I am so eager to know about how to characterize precipitates by XRD (specifically cementite, MX and M23C6 ). Any suggestions will be welcomed. :)
referred following link
Article XRD Analysis of Carbide Phase in Heat Resistant Steels
Dear Julio Cesar Gonzalez
First of all, are your precipitates amorphous or crystalline ones?
You may extract the intensity of the peaks from your diffraction, so you need a crystallographic model to work on for any further characterisation of the phases.
Known phases are straight related to the crystallographic databanks, like PDF, CCDC, COD and so on.
For the unknown phases, you may associate them to a similar structure, as far as you have some other complimentary information, like FXR data. They may part of a solid solution, with different stoichiometry and you can play with those data.
The calculation you intend to do is based on fitting your XRD with all known phases, subtracting the fitted ones from the experimental XRD. You may have, after all, the amorphous contribution to your diffraction.
That will give you an overview of the amorphous amount, since, for a full, reliable calculation, you need to know which phase is the amorphous one, to be able to calculate the area over the amorphous phase correctly, with the molecular weight of the corresponding mineral phase.
To safely do the analysis, you need more information, let say from a petrographic expert, fluorescence data to give you insights over the unknown specie.
In a completely different approach, you may get PDF (Pair Distribution Function) from your sample and treat your amorphous as a scattering phase. Unfortunately, this pathway needs a specific measurement, and the data treatment is not trivial.
Best regards,
WNM
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction