A novel technique to synthesize hydroxyapatite at low temperature

Hydroxyapatite (HAP), a well known biomaterial, was synthesized by a novel technique using agarose gel in a high alkaline medium at a relatively low temperature 85 °C. The XRD analysis of the as-synthesized material revealed the absence of either brushite or α or β tricalcium phosphate phases. Sintering studies at 750 and 1200 °C revealed the conversion of HAP into pyrophosphate without leaving any additional phases. A considerable decrease in the transformation temperature of HAP phase to that of α-calcium pyrophosphate (α-CPP) phase was found compared to the reported values.