Preparation of a material is much more then simply getting a few correct peaks in a single spectrum. Particle size is important. Crystallinity is important. Surface properties are important. Mechanical properties are important. And so on and so forth...

@Dr. Alexander

I know that preparation of material is much more important and to thoroughly understand the significance of each step during material synthesis is very much important for me as a young researcher. That is why i want to know the significance of sintering process for the synthesis of hydroxyapatite.

Dear Mr. Purohit,

If we are talking about chemically synthesized hydroxyapatite, it probably has physically and chemically adsorbed water, carbonate, nitrate and HPO4 groups.

After calcination or sintering, this by product peaks could disappear (belongs to the temperature). You can directly identify the peaks related to HA.

Before calcination also it is possible to determine the peaks, however, it requires much more attention.

Best regards.

You may want to check the following somewhat related discussion: https://www.researchgate.net/post/Can_anyone_explain_the_difference_between_FTIR_spectroscopy_of_sintered_hydroxyapatite_and_TCP