Stabilization of Calcium Oxyapatites with Lanthanum(III)-Created Anionic Vacancies

摘要: Two series of samples the system Ca 10-x La x (PO 4 ) 6 (OH) y (0 ≤ 2), have been synthesized by solid-state reaction at high temperature. In this composition range apatite structure is maintained. Cationic distribution was analyzed Rietveld refinement XRD data, showing a preferential substitution La(III) ions in Ca(2) position. The introduction trivalent ion provokes transformation OH - to O 2- ions. Stable oxy- or oxyhydroxyapatites with numerous anionic vacancies as function lanthanum content synthesis conditions.