Relationships between structural and luminescence properties in Eu3+-doped oxyphosphate–silicate apatite Ca2+xLa8−x(SiO4)6−x(PO4)xO2

The present paper reports the Eu 3+ fluorescence in the continuous solid solution Ca 2+x La 8 x(SiO4) 6-x (PO 4 ) x O 2 (x = 0,3,6) of the apatitic phosphate-silicates M 10 (XO 4 ) 6 Y 2 with M = Ca, La/X = P, Si and Y = O. Selective UV laser excitation, site-selective-laser excitation in the 5 D 0 level have been performed at 300 and 77 K 5 D 0 level decay times have been reported. In, these compounds, Eu 3+ can be observed in the three crystallographic positions Ca(I), Ca(II) and La(II) of the two cationic sites labeled M(I) (4f) C 3 symmetry and M(II) (6h) C s symmetry. The dominant one is found M(II) clue to an Eu - O privileged bonding with Eu 3+ located in (6h) positions either in La(II) or in Ca(II).