Hydrothermal Synthesis of Ultrafine Hydroxyapatite Single Crystals

Abstract

Hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2; HAp) ultrafine powders sy nthesized by a wet method were treated under hydrothermal conditions. The HAp particles obtained at 200°C under 2MPa for 10 h were hexagonal prism-shaped fine single crystals, about 25 nm×90 nm in size, the median aspect ratio obtained from the transmission electron micrograph. was 3.2. The quantitative chemical analysis, infrared (IR) spectra and X-ray diffraction (XRD), showed the presence of small amounts of CO 3 2- in the OH - site. The HAp could be given by the formula: Ca 10 (PO 4) 6 (OH) 1.81±0.03 (CO 3) 0.095±0.015. © 1988, The Chemical Society of Japan. All rights reserved.