On luminescence and energy transfer in oxyapatite co-doped with Eu3+ and Tb3+ ions.

Luminescence properties of oxyapatite co-doped ca8,9 tb1 eu0,1 (po4)6 o0.45[]1,55 with europium and terbium was studied,a comparative study of oxyapatites doped with only eu3+,tb3+ or both of these two ions,was conducted under laser excitations lines at 488 nm,457.9 nm and 337.1 nm. using a characteristic transition in the europium 5d0 ----- 7f0,1,2 and terbium5d4 ----- 7f5,4,3 spectra at 77 k. a significant energy transfer from tb3+ to eu3+ was evidenced for the co-doped oxyapatite. such energy transfer seems to occur via different mechanisms which involve particularly high levels of the ion tb3 + (5d3 or above).