Luminescent properties of Eu3+ in calcium hydroxyapatite

The time-resolved luminescence of the Eu3+ ion in calcium hydroxyapatite Ca -5(PO4)(3)OH prepared by a precipitation reaction is reported. The emission principally arises from the D-5(0) level. Site-selective excitation of the D-5(1) and D-5(2) levels was needed to distinguish very similar sites, lab elled A, B and C. The 20 K luminescence decay times of these three sites we re measured for the D-5(0) emitting level of Eu3+. The spectroscopic result s are considered in relation to the existence of different crystallographic sites for Eu3+ in this material and in terms of possible charge compensati on mechanisms. (C) 1999 Elsevier Science B.V. All rights reserved.