I am getting broadened XRD pattern after annealing the as prepared sample. So I would like to know the possible reasons for this. My query is also to know microscopically what happens in such cases of sharpening and broadening of peaks in XRD pattern.
Annealing can cause the coarsening or densification processes, it depend on material, temperature and the material. If the XRD pattern become sharp it means that the coarsening process more dominant than densification. The particle size will increase. But if the densification more dominant than coarsening, the broadening pattern will occur and the particle size will decrease. That is why nanocrystalline will show larger FWHM than bulk material (non nano).
The broadening of the X-ray diffraction peaks after annealing is required to reduce the particle size. Peake width - full width at half maximum. Importent for particle or grain size. Resudial strain. As grain size decreses hardness increases and peakes become broader. No strain (peake does not move relative to the standard). Uniform strain (peake moves, no shape change). Non-uniform strain (peake broadense).
Best regards.
Annealing can cause the coarsening or densification processes, it depend on material, temperature and the material. If the XRD pattern become sharp it means that the coarsening process more dominant than densification. The particle size will increase. But if the densification more dominant than coarsening, the broadening pattern will occur and the particle size will decrease. That is why nanocrystalline will show larger FWHM than bulk material (non nano).
Thank you Yuri Mirgorod Sir and Posman Manurung Sir. What about the role of impurities (if any) in the system and how it will affect the coarsening and densification?
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