Novel Sol- Gel Synthesis and Characterization of Nanostructured Hydroxyapatite Powder

Nanocrystalline powders of hydroxyapatite (HA) were prepared from Ca(NO3)2·4H2O and P2O5 using a simple sol–gel approach. The resultant gel precursors obtained based on the concentration of the starting solutions were either transparent or translucent. Fourier transform-infrared spectroscopy (FT-IR) results combined with the X-ray diffraction (XRD)indicated the presence of amorphous HA in the as-dried gel precursor. Xray patterns collected on the powder after heat-treatment at 900 °C for 12 h in air exhibited single phase of HA. Scanning electron microscopy (SEM) showed that nanocrystalline (50 nm) HA particles have obtained in the powder after heat treatment at 900◦C.