Raman study of apatite coating, obtained by detonation spraying of the precursor salts on the titanium substrates

The results of the Raman study of the apatite coatings, obtained by detonation spraying of the precursor salts on the titanium substrates are presented. The mixture of Ca(OH)2 and (NH4)2HPO4 salts at the molar ratio 5:3 was used as precursors. A detailed analysis of the most intense Raman band showed hydroxyapatite formation with a dominant contribution of the amorphous phase. The post-deposition thermal annealing at 640 °C for 30 min in the Ar atmosphere leads to the transformation of the amorphous hydroxylapatite into the crystalline one. •The apatite coatings of the titanium substrates can be obtained by gas-detonation deposition.•The mixture of Ca(OH)2 and (NH4)2HPO4 salts at the ratio 5:3 can be used as precursor.•The warming of the powder particles causes the forming of the amorphous HAP coating.•The thermal annealing allows the transforming of the amorphous HAP into the crystalline one.