When we synthesized the same compounds at different temperatures, the XRD peaks appeared at the same positions. But the relative intensity of the characteristic peaks changed. For example, the ratio of the intensities of 012 and 022 was changed from 0.8:1 to 1:5. Does it indicate that the amount of 022 is increased? Thanks.
It is related to the crystallinity of the sample. The higher intensity values indicate higher XRD scores of the sample.
Fatma Tuğçe Şenberber Dumanlı : the crystallinity in my opinion is - at least as it concerns hard condensed matter a relatively ill-defined concept.
Concerning the question: First be sure whether you speak about the ratio of peak-maximum intensities or of integrated intensities. The latter ones are the the "more invariant" quantities, so a question like the above one should be asked when referring to integrated intentities.
There are several possible origins of the described change in the reflection (integrated) intensities. Their likeliness (it is unclear whether it is a deposited layer or a conventional polycrystalline solid/powder)
1. Different degrees of texture in the two sets of specimens used for diffration
2. Some variation of the unit cell contents as a function of the treatment procedure changing the structure factors and thus the intensities. What about the lattice parameters in this context: They would typically be affected by such unit cell content changes.
3. Differently pronounced instrumental abberations, e.g. surface roughness, sample thickness. Severe effects on the integrated intensities are, however, only expected for very-low-angle reflections.
Based on your material under consideration and your experimental setup, you have to find out what is most likely. Best do not only consider the information from the two reflections but consider the whole patterns.
The intensity of the peak in this case reflects the quantity of the mineral phase characteristic of the peak. This quantity is all the greater as the intensity is great. The crystallinity does not depend of the intensity but more to the width at mid-height of the peak. Indeed, for relatively thin peaks we would have better crystallinity compared to larger ones!
When you synthesis some compounds at different temperatures, crystallinity will changed and in some cases disarray will appeared in crystals so you will got different intensity
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