Synthesis and characterization of the copper doped Ca-La apatites. (October 2016) - Pogosova, M.A.
Abstract: Copper-containing Ca-La hydroxyapatites (HAPs) with chemical compositions Ca10- x La x (PO4 )6 O2 H1.5- x - y - δ Cu y ( x = 0–1.79; y = 0–0.57) were synthesized by solid state reaction. Structural parameters and atomic positions were refined using the Rietveld method in space group P 63 / m . It was found that La 3+ ions occupied the Ca(2) position only and copper ions were located mainly inside the hexagonal channel. In contrast to known red-violet copper-doped Ca-apatites, the copper-doped Ca-La apatites exhibited lighter colors varying from pink to pale yellow and blue-grey tints. Chromophores in the compounds were characterized by diffuse reflectance spectroscopy, colorimetry, and resonant Raman spectroscopy. Highlights: New colored copper-doped apatite-type materials were synthesized. Positions of the La and Cu ions in the crystal lattice were determined. Relationships between crystal structure and spectral characteristics were described. Specific chromophore centres were characterized.