EU3+-O2- ASSOCIATES LUMINESCENCE IN BA2SIO4

Results on the luminescence properties of Eu3+ in Ba2SiO4 sites and th e presence of Eu3+-O2- associates are reported. The Ba2SiO4:Eu3+ emiss ion spectra showed two groups of transitions that might be assigned to the D-5(0) --> F-7(0) one. In each group at least two lines were obse rved. This is possibly related to the different emission centers, attr ibuted to Eu3+ occupying the Ba2+ sites, and to Eu3+-O2- associates in interstices. Excitation spectra presented two CT bands at 270 and 340 nm related to each emission center.