Synthesis and Optical Properties of Eu3+Ion Doped Nanocrystalline Hydroxyapatites

The Ca10(PO4)6(OH)2 hydroxyapatite (HA) nanopowders doped with Eu3+ ions were prepared using a wet synthesis method. Their structure and morphology were investigated. The XRD analysis has proven a single-phase of HA nanocrystallites. The average sizes of HA nanocrystallites calcinated at 400°C and 700°C were determined to be about 20 nm and 30 nm, respectively. The emission and excitation spectra as well as the fluorescence decay rates of Eu3+ ion doped HA nanocrystallites were measured. Particular attention was given to the spectroscopic properties of Eu3+ ions as a luminescent probe of nanocrystalline HA structure as a result of varying annealing temperature and dopant concentration. The Judd-Ofelt analysis of f-f transitions of Eu3+:HA nanocrystallites was performed. The effect of calcination temperatures on grain sizes and luminescence properties is noted and discussed.