Synthesis of potassium chloroapatites, IR, X-ray and Raman studies

Abstract

New conditions of synthesis Ca-chlorapatite and K-Ca-chlorapatite by using the melt salts method were determined. The results of X-ray diffraction show that the compound Ca-chlorapatite crystallizes in the hexagonal system (space group P63/m) with the crystallo-graphic parameters (a = b = 9.6228(3) Å and c = 6.7610(3) Å) that are closely equal to those of literature. Two potassium calcium chlorapatites were prepared by this method. Samples were identified by X.R diffraction, IR spectroscopy, chemical analysis and density measurements. Results allow to propose a global general formula (Ca 10-xKx(PO4)6(Cl)2-x with 0 < x < 2). IR absorption and Raman diffusion studies allow to attribute different modes of vibration and to show the structural disorder. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.