Synthetic hydroxiapatites doped with Zn(II) studied by X-ray diffraction, infrared, Raman and thermal analysis

JOSÉ R.GUERRA-LÓPEZ; GUSTAVO A. ECHEVERRÍA; JORGE A. GÜIDA; GRACIELAPUNTE

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 81 p. 57 - 65

0022-3697

Calcium hydroxyapatite (CaHap) formation when different amounts of Zn(II) are present in the mother solution has been investigated by atomic absorption, infrared and Raman spectroscopies, X-ray diffraction and thermal analysis (DTAandTG). The studied samples have been synthesized at T=95 °C and pH 9 in air. The analysis of the results have shown that the pure CaHap sample crystallizes in the monoclinic form P21/b. Concentrations up to 20% of Zn(II) in the mother solution, equivalent to smaller concentrations in solid (upto9.1%inwt), favor the formation of the hexagonalapatite, P63/m, whileZn(II) concentrations higher than 20% in solution help an amorphous phase development where vibrational spectra indicated coexistence of two phases: anapatite and ZnNH4PO4 H2O. Infrared data of thermal treated samples endorse that HPO4 2 ion had no tbeen incorporated in Zn(II) doped samples during the synthesis process. Present results als oallow to conclude that Zn(II) cation exhibits a preference to occupy the Ca2 site of the apatite structure and induces water adsorption and a small quantity of CO3 2 cation incorporation, leading to formation of a less crystalline Ca deficient apatite.