Abstract
1H MAS NMR spectra have been successfully obtained for hydroxyapatite samples heat-treated at temperatures of 200-1200 °C. The intensity of bands around 0 ppm associated with the OH- ions did not change significantly up to about 800 °C, whereas it decreased at temperatures higher than about 800 °C. The peak shifted into a downfield (a light shielded environment) and the line width increased with increasing temperature at higher than 800 °C. These results are interpreted in terms of disordered environments around the OH- sites due to creation of defects by dehydration of hydroxyapatite over 800 °C.
