Do you mean hydroxyapatite? Ca10(PO4)6(OH)2? For this compound there are many synthesis routes, from co-precipitation to hydrothermal, solid state...search in the proper literature, there are plenty of papers...

Thank you very much, Dr. Bini

@ Uvin, the attached file may be useful to you.

Please refer this paper.

DEAR DR EVIEN

Certainly, preparing hydroxyapatite (HA) nanoparticles involves several steps, and it's important to have a clear understanding of the process to ensure successful synthesis. Hydroxyapatite is a biocompatible material often used in various biomedical and dental applications. Here's a general outline of the synthesis process:

1. Chemical Precursors:You'll need calcium and phosphate sources as your main precursors. Common choices are calcium nitrate or calcium chloride for the calcium source, and diammonium hydrogen phosphate or ammonium dihydrogen phosphate for the phosphate source.

2. Mixing:Dissolve the calcium and phosphate precursors in deionized water separately to create two solutions. Then, add the phosphate solution dropwise into the calcium solution under constant stirring. This will lead to the precipitation of hydroxyapatite.

3. pH Adjustment:The pH of the mixture is critical for obtaining pure hydroxyapatite. Adjust the pH to around 9-10 using a base (like ammonium hydroxide or sodium hydroxide) to promote HA formation.

4. Aging:Allow the mixture to age for a certain period, typically several hours to overnight. During aging, the nanoparticles will grow and form stable structures.

5. Filtration and Washing:After aging, the precipitate is usually separated by filtration and washed with deionized water to remove any residual chemicals and impurities.

6. Drying:Dry the obtained precipitate in an oven at a temperature around 60-80°C. This will result in the formation of hydroxyapatite nanoparticles.