Abstract
The biological apatites contain minor substituents such as F-, Cl-, CO32-, Na+, Sr2+, Mg2+ ... Therefore, the incorporation of such ions into the synthetic hydroxyapatite would enhance its biocompatibility and bioactivity. Magnesium and fluoride co-substituted hydroxyapatites with the general chemical formula Ca9Mg(PO4)(6)(OH)(2-y)F-y, where 0 <= y <= 2, have been synthesized through a hydrothermal method. The obtained powders have been characterized using the chemical analysis, X-ray diffraction, infrared spectroscopy, nuclear magnetic resonance, specific surface area measurements, scanning electron microscopy, transmission electron microscopy and thermogravimetry. The results showed that the substitution of F- for OH- was continuous between the limiting compositions Ca9Mg(PO4)(6)(OH)(2) and Ca9Mg(PO4)(6)F-2. Indeed, no secondary phases were formed. Furthermore, the incorporation of F into the Mg-substituted hydroxyapatite lattice influenced its thermal behavior by increasing its decomposition temperature and changing the nature of the formed products with the inserted fluorine content.