Sol–gel derived hydroxyapatite films on alumina substrates

The crystallinity and structural changes of hydroxyapatite films prepared on alumina substrates using a sol–gel process were analyzed by X-ray diffraction (XRD) θ−2θ scans and Fourier transform infrared (FTIR) spectroscopy. Hydroxyapatite films, confirmed by XRD θ−2θ scanning, were obtained by heat treatment at 500 and 700°C from the pre-fired films. A film heat treated at 700°C showed the strongest peak intensities. For a film heat-treated at 500°C, the FTIR and XRD results indicated that carbonate was substituted into the hydroxyapatite lattice.