Optical properties of LnPO4 : Eu3+ (Ln = Y, La and Gd) powder phosphors

The synthesis,single and dual host compositional effects on the fluorescence spectra of Eu3+-doped YPO4, LaPO4, GdPO4, (La,Gd)PO4, (La,Y)PO4 and (Cd,Y)P04 powder phosphors are studied. From the fluorescence spectra the emission transition D-5(0) --> F-7(1) has been found to be more prominent over the normal red emission transition (D-5(0) --> F-7(2)). Under a UV-source these phosphors have been fluorescent in orange-red color, The observed absorption frequencies (nu ,cm(-1)) are reported from the measured FT-IR spectra. Scanning electron microscopic investigations are carried out to understand the surface morphological features and the grain size, The room temperature lifetime measurements are made for the two emission transitions (D-5(0) --> F-7(1.2)) of all these phosphors. Qualitative analysis of the elements (Y, La, Gd, Eu, O and P) has been carried out by the SEM/EDAX technique. (C) 2001 Published by Elsevier Science B.V.