Mechanochemical Synthesis of Carbonate- and Fluoride-Substituted Hydroxyapatite

Hydroxyapatite, fluoroapatite, and hydroxyapatite with partial substitution by fluoride and carbonate ions were obtained through mechanochemical synthesis. When a fluoride ion is introduced into the structure of hydroxyapatite, the substitution of the hydroxyl group occurs, while carbonate ion substitutes the phosphate group. Lattice parameters and the CSR of the samples were refined using the Rietveld method. It was found that the introduction of substituents into the structure of hydroxyapatite reduces the lattice parameters, which is due to the smaller size of substituting ions. The synthesized powders can be used in medicine as bioresorbable materials.