Preparative Enhancement of the Thermal Stability of Calcium Hydroxyapatites

The thermal stability of calcium hydroxyapatites (CaHAp) as prepared by traditional methods is quite low, with the preponderance of CaHAp being converted to Ca3(PO4)2at temperatures as low as 973 K. In contrast, control of the pH during preparation markedly enhances the thermal stability of CaHAp, with retention of its appropriate chemical composition and structural features.