Luminescence properties of Eu2+ and Eu3+ doped calcium-deficient hydroxyapatite prepared in air

Eu-doped calcium-deficient hydroxyapatite Ca8.95Eu0.05HPO4(PO4)(5)OH (designated CDHA:Eu) was prepared via the coprecipitation method and calcined in air. Phase purity, crystal structure and morphology of the CDHA: Eu were characterized using X-ray diffraction spectrometer and scanning electron microscopy. The photoluminescence excitation and emission spectra of Eu2+ and Eu3+ ions were measured using luminescence spectrometer. The emission spectra showed a broad emission band centered at 450nm corresponded to the typical 4f(6)5d(1) -> 4f(7) transition of Eu2+ ions, and sharp peaks corresponded to the D-5(0) > F-7(J) (J = 0, 1, 2, 3, 4) transitions of Eu3+ ions. This research was focused on the site-distribution of Eu3+ ions. The Eu3+ in different sites had different spectroscopic features and the charge compensation mechanisms were also discussed. (C) 2011 Elsevier B.V. All rights reserved.