Mechanochemical-hydrothermal synthesis of calcium phosphate powders with coupled magnesium and carbonate substitution

Magnesium- and carbonate-substituted calcium phosphate powders (Mg-, CO3-CaP) with various crystallinity levels were prepared at room temperature via a heterogeneous reaction between MgCO3/Ca(OH)(2) powders and an (NH4)(2)HPO4 Solution using the mechanochemical-hydrothermal route. X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis were performed. It was determined that the powders containing both Mg2+ and CO32- ions were incorporated uniformly into all amorphous calcium phosphate phase while in contrast, the as-prepared powder free of these dopants was crystalline phase-pure, stoichiometric hydroxyapatitc. Dynamic light scattering revealed that the average particle size of the room temperature Mg-, CO3-CaP powders was in the range of 482 nm-700 nm nm with a specific surface area between 53 and 91 m(2)/g. Scanning clectron microscopy confirmed that the Mg-, CO3-CaP powders consisted of agglomerates of equiaxed, 20-35 nm crystals. (C) 2003 Elsevier Inc. All rights reserved.