Kristallographisches und spektroskopisches Verhalten einiger gemischter Phosphat/Vanadat-Fluoroapatite / Crystallographic and Spectroscopic Behaviour of Some Mixed Phosphate/Vanadate Fluoroapatites

Abstract

Abstract Crystallographic data for mixed phosphate/vanadate fluoroapatites of the type M10(PO4)6−x(VO4)xF2 (with M = Ca, Sr, Ba and x = 1-3) have been obtained from X-ray powder data. The only structural effect observed is a continuous increase of unit cell dimensions with increased vanadate incorporation. The IR and Raman spectra show that the VO4 3− incorporation has a negligible effect on the strength of the P - O bonds, although a small bond weakening for both tetrahedral oxoanions is observed as the unit cell volume increases. The results are comparable to those reported earlier for similar mixed hydroxyapatites and suggest that the fluoroapatite lattice can be considered as a good “model” for the vertebrate hard tissues.